selftests/mm temporary fix of hmm infinate loop #3
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jira SECO-170 In Rocky9 if you run ./run_vmtests.sh -t hmm it will fail and cause an infinate loop on ASSERTs in FIXTURE_TEARDOWN() This temporary fix is based on the discussion here https://patchwork.kernel.org/project/linux-kselftest/patch/[email protected]/#25046055 We will investigate further kselftest updates that will resolve the root causes of this.
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PlaidCat
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jira LE-2015 cve CVE-2024-40904 Rebuild_History Non-Buildable kernel-5.14.0-427.42.1.el9_4 commit-author Alan Stern <[email protected]> commit 22f0081 The syzbot fuzzer found that the interrupt-URB completion callback in the cdc-wdm driver was taking too long, and the driver's immediate resubmission of interrupt URBs with -EPROTO status combined with the dummy-hcd emulation to cause a CPU lockup: cdc_wdm 1-1:1.0: nonzero urb status received: -71 cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625] CPU#0 Utilization every 4s during lockup: #1: 98% system, 0% softirq, 3% hardirq, 0% idle #2: 98% system, 0% softirq, 3% hardirq, 0% idle #3: 98% system, 0% softirq, 3% hardirq, 0% idle #4: 98% system, 0% softirq, 3% hardirq, 0% idle #5: 98% system, 1% softirq, 3% hardirq, 0% idle Modules linked in: irq event stamp: 73096 hardirqs last enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline] hardirqs last enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994 hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline] hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551 softirqs last enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline] softirqs last enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582 softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588 CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G W 6.10.0-rc2-syzkaller-g8867bbd4a056 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Testing showed that the problem did not occur if the two error messages -- the first two lines above -- were removed; apparently adding material to the kernel log takes a surprisingly large amount of time. In any case, the best approach for preventing these lockups and to avoid spamming the log with thousands of error messages per second is to ratelimit the two dev_err() calls. Therefore we replace them with dev_err_ratelimited(). Signed-off-by: Alan Stern <[email protected]> Suggested-by: Greg KH <[email protected]> Reported-and-tested-by: [email protected] Closes: https://lore.kernel.org/linux-usb/[email protected]/ Reported-and-tested-by: [email protected] Closes: https://lore.kernel.org/linux-usb/[email protected]/ Fixes: 9908a32 ("USB: remove err() macro from usb class drivers") Link: https://lore.kernel.org/linux-usb/[email protected]/ Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> (cherry picked from commit 22f0081) Signed-off-by: Jonathan Maple <[email protected]>
PlaidCat
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Its used from trace__run(), for the 'perf trace' live mode, i.e. its
strace-like, non-perf.data file processing mode, the most common one.
The trace__run() function will set trace->host using machine__new_host()
that is supposed to give a machine instance representing the running
machine, and since we'll use perf_env__arch_strerrno() to get the right
errno -> string table, we need to use machine->env, so initialize it in
machine__new_host().
Before the patch:
(gdb) run trace --errno-summary -a sleep 1
<SNIP>
Summary of events:
gvfs-afc-volume (3187), 2 events, 0.0%
syscall calls errors total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- ------ -------- --------- --------- --------- ------
pselect6 1 0 0.000 0.000 0.000 0.000 0.00%
GUsbEventThread (3519), 2 events, 0.0%
syscall calls errors total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- ------ -------- --------- --------- --------- ------
poll 1 0 0.000 0.000 0.000 0.000 0.00%
<SNIP>
Program received signal SIGSEGV, Segmentation fault.
0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
478 if (env->arch_strerrno == NULL)
(gdb) bt
#0 0x00000000005caba0 in perf_env__arch_strerrno (env=0x0, err=110) at util/env.c:478
#1 0x00000000004b75d2 in thread__dump_stats (ttrace=0x14f58f0, trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4673
#2 0x00000000004b78bf in trace__fprintf_thread (fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>, thread=0x10fa0b0, trace=0x7fffffffa5b0) at builtin-trace.c:4708
#3 0x00000000004b7ad9 in trace__fprintf_thread_summary (trace=0x7fffffffa5b0, fp=0x7ffff6ff74e0 <_IO_2_1_stderr_>) at builtin-trace.c:4747
#4 0x00000000004b656e in trace__run (trace=0x7fffffffa5b0, argc=2, argv=0x7fffffffde60) at builtin-trace.c:4456
#5 0x00000000004ba43e in cmd_trace (argc=2, argv=0x7fffffffde60) at builtin-trace.c:5487
#6 0x00000000004c0414 in run_builtin (p=0xec3068 <commands+648>, argc=5, argv=0x7fffffffde60) at perf.c:351
#7 0x00000000004c06bb in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:404
#8 0x00000000004c0814 in run_argv (argcp=0x7fffffffdc4c, argv=0x7fffffffdc40) at perf.c:448
#9 0x00000000004c0b5d in main (argc=5, argv=0x7fffffffde60) at perf.c:560
(gdb)
After:
root@number:~# perf trace -a --errno-summary sleep 1
<SNIP>
pw-data-loop (2685), 1410 events, 16.0%
syscall calls errors total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- ------ -------- --------- --------- --------- ------
epoll_wait 188 0 983.428 0.000 5.231 15.595 8.68%
ioctl 94 0 0.811 0.004 0.009 0.016 2.82%
read 188 0 0.322 0.001 0.002 0.006 5.15%
write 141 0 0.280 0.001 0.002 0.018 8.39%
timerfd_settime 94 0 0.138 0.001 0.001 0.007 6.47%
gnome-control-c (179406), 1848 events, 20.9%
syscall calls errors total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- ------ -------- --------- --------- --------- ------
poll 222 0 959.577 0.000 4.322 21.414 11.40%
recvmsg 150 0 0.539 0.001 0.004 0.013 5.12%
write 300 0 0.442 0.001 0.001 0.007 3.29%
read 150 0 0.183 0.001 0.001 0.009 5.53%
getpid 102 0 0.101 0.000 0.001 0.008 7.82%
root@number:~#
Fixes: 54373b5 ("perf env: Introduce perf_env__arch_strerrno()")
Reported-by: Veronika Molnarova <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Acked-by: Veronika Molnarova <[email protected]>
Acked-by: Michael Petlan <[email protected]>
Tested-by: Michael Petlan <[email protected]>
Link: https://lore.kernel.org/r/Z0XffUgNSv_9OjOi@x1
Signed-off-by: Namhyung Kim <[email protected]>
PlaidCat
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This reworks hci_cb_list to not use mutex hci_cb_list_lock to avoid bugs
like the bellow:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u9:2/5070:
#0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
#0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
#1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
#1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
#2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
#3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
__might_resched+0x5d4/0x780 kernel/sched/core.c:10187
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
hci_event_func net/bluetooth/hci_event.c:7514 [inline]
hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
kthread+0x2f0/0x390 kernel/kthread.c:388
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
</TASK>
Reported-by: [email protected]
Tested-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
PlaidCat
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This fixes the circular locking dependency warning below, by releasing the socket lock before enterning iso_listen_bis, to avoid any potential deadlock with hdev lock. [ 75.307983] ====================================================== [ 75.307984] WARNING: possible circular locking dependency detected [ 75.307985] 6.12.0-rc6+ #22 Not tainted [ 75.307987] ------------------------------------------------------ [ 75.307987] kworker/u81:2/2623 is trying to acquire lock: [ 75.307988] ffff8fde1769da58 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO) at: iso_connect_cfm+0x253/0x840 [bluetooth] [ 75.308021] but task is already holding lock: [ 75.308022] ffff8fdd61a10078 (&hdev->lock) at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth] [ 75.308053] which lock already depends on the new lock. [ 75.308054] the existing dependency chain (in reverse order) is: [ 75.308055] -> #1 (&hdev->lock){+.+.}-{3:3}: [ 75.308057] __mutex_lock+0xad/0xc50 [ 75.308061] mutex_lock_nested+0x1b/0x30 [ 75.308063] iso_sock_listen+0x143/0x5c0 [bluetooth] [ 75.308085] __sys_listen_socket+0x49/0x60 [ 75.308088] __x64_sys_listen+0x4c/0x90 [ 75.308090] x64_sys_call+0x2517/0x25f0 [ 75.308092] do_syscall_64+0x87/0x150 [ 75.308095] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 75.308098] -> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}: [ 75.308100] __lock_acquire+0x155e/0x25f0 [ 75.308103] lock_acquire+0xc9/0x300 [ 75.308105] lock_sock_nested+0x32/0x90 [ 75.308107] iso_connect_cfm+0x253/0x840 [bluetooth] [ 75.308128] hci_connect_cfm+0x6c/0x190 [bluetooth] [ 75.308155] hci_le_per_adv_report_evt+0x27b/0x2f0 [bluetooth] [ 75.308180] hci_le_meta_evt+0xe7/0x200 [bluetooth] [ 75.308206] hci_event_packet+0x21f/0x5c0 [bluetooth] [ 75.308230] hci_rx_work+0x3ae/0xb10 [bluetooth] [ 75.308254] process_one_work+0x212/0x740 [ 75.308256] worker_thread+0x1bd/0x3a0 [ 75.308258] kthread+0xe4/0x120 [ 75.308259] ret_from_fork+0x44/0x70 [ 75.308261] ret_from_fork_asm+0x1a/0x30 [ 75.308263] other info that might help us debug this: [ 75.308264] Possible unsafe locking scenario: [ 75.308264] CPU0 CPU1 [ 75.308265] ---- ---- [ 75.308265] lock(&hdev->lock); [ 75.308267] lock(sk_lock- AF_BLUETOOTH-BTPROTO_ISO); [ 75.308268] lock(&hdev->lock); [ 75.308269] lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO); [ 75.308270] *** DEADLOCK *** [ 75.308271] 4 locks held by kworker/u81:2/2623: [ 75.308272] #0: ffff8fdd66e52148 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work+0x443/0x740 [ 75.308276] #1: ffffafb488b7fe48 ((work_completion)(&hdev->rx_work)), at: process_one_work+0x1ce/0x740 [ 75.308280] #2: ffff8fdd61a10078 (&hdev->lock){+.+.}-{3:3} at: hci_le_per_adv_report_evt+0x47/0x2f0 [bluetooth] [ 75.308304] #3: ffffffffb6ba4900 (rcu_read_lock){....}-{1:2}, at: hci_connect_cfm+0x29/0x190 [bluetooth] Fixes: 02171da ("Bluetooth: ISO: Add hcon for listening bis sk") Signed-off-by: Iulia Tanasescu <[email protected]> Signed-off-by: Luiz Augusto von Dentz <[email protected]>
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…s_lock For storing a value to a queue attribute, the queue_attr_store function first freezes the queue (->q_usage_counter(io)) and then acquire ->sysfs_lock. This seems not correct as the usual ordering should be to acquire ->sysfs_lock before freezing the queue. This incorrect ordering causes the following lockdep splat which we are able to reproduce always simply by accessing /sys/kernel/debug file using ls command: [ 57.597146] WARNING: possible circular locking dependency detected [ 57.597154] 6.12.0-10553-gb86545e02e8c #20 Tainted: G W [ 57.597162] ------------------------------------------------------ [ 57.597168] ls/4605 is trying to acquire lock: [ 57.597176] c00000003eb56710 (&mm->mmap_lock){++++}-{4:4}, at: __might_fault+0x58/0xc0 [ 57.597200] but task is already holding lock: [ 57.597207] c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4 [ 57.597226] which lock already depends on the new lock. [ 57.597233] the existing dependency chain (in reverse order) is: [ 57.597241] -> #5 (&sb->s_type->i_mutex_key#3){++++}-{4:4}: [ 57.597255] down_write+0x6c/0x18c [ 57.597264] start_creating+0xb4/0x24c [ 57.597274] debugfs_create_dir+0x2c/0x1e8 [ 57.597283] blk_register_queue+0xec/0x294 [ 57.597292] add_disk_fwnode+0x2e4/0x548 [ 57.597302] brd_alloc+0x2c8/0x338 [ 57.597309] brd_init+0x100/0x178 [ 57.597317] do_one_initcall+0x88/0x3e4 [ 57.597326] kernel_init_freeable+0x3cc/0x6e0 [ 57.597334] kernel_init+0x34/0x1cc [ 57.597342] ret_from_kernel_user_thread+0x14/0x1c [ 57.597350] -> #4 (&q->debugfs_mutex){+.+.}-{4:4}: [ 57.597362] __mutex_lock+0xfc/0x12a0 [ 57.597370] blk_register_queue+0xd4/0x294 [ 57.597379] add_disk_fwnode+0x2e4/0x548 [ 57.597388] brd_alloc+0x2c8/0x338 [ 57.597395] brd_init+0x100/0x178 [ 57.597402] do_one_initcall+0x88/0x3e4 [ 57.597410] kernel_init_freeable+0x3cc/0x6e0 [ 57.597418] kernel_init+0x34/0x1cc [ 57.597426] ret_from_kernel_user_thread+0x14/0x1c [ 57.597434] -> #3 (&q->sysfs_lock){+.+.}-{4:4}: [ 57.597446] __mutex_lock+0xfc/0x12a0 [ 57.597454] queue_attr_store+0x9c/0x110 [ 57.597462] sysfs_kf_write+0x70/0xb0 [ 57.597471] kernfs_fop_write_iter+0x1b0/0x2ac [ 57.597480] vfs_write+0x3dc/0x6e8 [ 57.597488] ksys_write+0x84/0x140 [ 57.597495] system_call_exception+0x130/0x360 [ 57.597504] system_call_common+0x160/0x2c4 [ 57.597516] -> #2 (&q->q_usage_counter(io)#21){++++}-{0:0}: [ 57.597530] __submit_bio+0x5ec/0x828 [ 57.597538] submit_bio_noacct_nocheck+0x1e4/0x4f0 [ 57.597547] iomap_readahead+0x2a0/0x448 [ 57.597556] xfs_vm_readahead+0x28/0x3c [ 57.597564] read_pages+0x88/0x41c [ 57.597571] page_cache_ra_unbounded+0x1ac/0x2d8 [ 57.597580] filemap_get_pages+0x188/0x984 [ 57.597588] filemap_read+0x13c/0x4bc [ 57.597596] xfs_file_buffered_read+0x88/0x17c [ 57.597605] xfs_file_read_iter+0xac/0x158 [ 57.597614] vfs_read+0x2d4/0x3b4 [ 57.597622] ksys_read+0x84/0x144 [ 57.597629] system_call_exception+0x130/0x360 [ 57.597637] system_call_common+0x160/0x2c4 [ 57.597647] -> #1 (mapping.invalidate_lock#2){++++}-{4:4}: [ 57.597661] down_read+0x6c/0x220 [ 57.597669] filemap_fault+0x870/0x100c [ 57.597677] xfs_filemap_fault+0xc4/0x18c [ 57.597684] __do_fault+0x64/0x164 [ 57.597693] __handle_mm_fault+0x1274/0x1dac [ 57.597702] handle_mm_fault+0x248/0x484 [ 57.597711] ___do_page_fault+0x428/0xc0c [ 57.597719] hash__do_page_fault+0x30/0x68 [ 57.597727] do_hash_fault+0x90/0x35c [ 57.597736] data_access_common_virt+0x210/0x220 [ 57.597745] _copy_from_user+0xf8/0x19c [ 57.597754] sel_write_load+0x178/0xd54 [ 57.597762] vfs_write+0x108/0x6e8 [ 57.597769] ksys_write+0x84/0x140 [ 57.597777] system_call_exception+0x130/0x360 [ 57.597785] system_call_common+0x160/0x2c4 [ 57.597794] -> #0 (&mm->mmap_lock){++++}-{4:4}: [ 57.597806] __lock_acquire+0x17cc/0x2330 [ 57.597814] lock_acquire+0x138/0x400 [ 57.597822] __might_fault+0x7c/0xc0 [ 57.597830] filldir64+0xe8/0x390 [ 57.597839] dcache_readdir+0x80/0x2d4 [ 57.597846] iterate_dir+0xd8/0x1d4 [ 57.597855] sys_getdents64+0x88/0x2d4 [ 57.597864] system_call_exception+0x130/0x360 [ 57.597872] system_call_common+0x160/0x2c4 [ 57.597881] other info that might help us debug this: [ 57.597888] Chain exists of: &mm->mmap_lock --> &q->debugfs_mutex --> &sb->s_type->i_mutex_key#3 [ 57.597905] Possible unsafe locking scenario: [ 57.597911] CPU0 CPU1 [ 57.597917] ---- ---- [ 57.597922] rlock(&sb->s_type->i_mutex_key#3); [ 57.597932] lock(&q->debugfs_mutex); [ 57.597940] lock(&sb->s_type->i_mutex_key#3); [ 57.597950] rlock(&mm->mmap_lock); [ 57.597958] *** DEADLOCK *** [ 57.597965] 2 locks held by ls/4605: [ 57.597971] #0: c0000000137c12f8 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0xcc/0x154 [ 57.597989] #1: c0000018e27c6810 (&sb->s_type->i_mutex_key#3){++++}-{4:4}, at: iterate_dir+0x94/0x1d4 Prevent the above lockdep warning by acquiring ->sysfs_lock before freezing the queue while storing a queue attribute in queue_attr_store function. Later, we also found[1] another function __blk_mq_update_nr_ hw_queues where we first freeze queue and then acquire the ->sysfs_lock. So we've also updated lock ordering in __blk_mq_update_nr_hw_queues function and ensured that in all code paths we follow the correct lock ordering i.e. acquire ->sysfs_lock before freezing the queue. [1] https://lore.kernel.org/all/CAFj5m9Ke8+EHKQBs_Nk6hqd=LGXtk4mUxZUN5==ZcCjnZSBwHw@mail.gmail.com/ Reported-by: [email protected] Fixes: af28141 ("block: freeze the queue in queue_attr_store") Tested-by: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Signed-off-by: Nilay Shroff <[email protected]> Reviewed-by: Ming Lei <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
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jira LE-1907 Rebuild_History Non-Buildable kernel-rt-5.14.0-284.30.1.rt14.315.el9_2 commit-author minoura makoto <[email protected]> commit b18cba0 Commit 9130b8d ("SUNRPC: allow for upcalls for the same uid but different gss service") introduced `auth` argument to __gss_find_upcall(), but in gss_pipe_downcall() it was left as NULL since it (and auth->service) was not (yet) determined. When multiple upcalls with the same uid and different service are ongoing, it could happen that __gss_find_upcall(), which returns the first match found in the pipe->in_downcall list, could not find the correct gss_msg corresponding to the downcall we are looking for. Moreover, it might return a msg which is not sent to rpc.gssd yet. We could see mount.nfs process hung in D state with multiple mount.nfs are executed in parallel. The call trace below is of CentOS 7.9 kernel-3.10.0-1160.24.1.el7.x86_64 but we observed the same hang w/ elrepo kernel-ml-6.0.7-1.el7. PID: 71258 TASK: ffff91ebd4be0000 CPU: 36 COMMAND: "mount.nfs" #0 [ffff9203ca3234f8] __schedule at ffffffffa3b8899f ctrliq#1 [ffff9203ca323580] schedule at ffffffffa3b88eb9 ctrliq#2 [ffff9203ca323590] gss_cred_init at ffffffffc0355818 [auth_rpcgss] ctrliq#3 [ffff9203ca323658] rpcauth_lookup_credcache at ffffffffc0421ebc [sunrpc] ctrliq#4 [ffff9203ca3236d8] gss_lookup_cred at ffffffffc0353633 [auth_rpcgss] ctrliq#5 [ffff9203ca3236e8] rpcauth_lookupcred at ffffffffc0421581 [sunrpc] ctrliq#6 [ffff9203ca323740] rpcauth_refreshcred at ffffffffc04223d3 [sunrpc] ctrliq#7 [ffff9203ca3237a0] call_refresh at ffffffffc04103dc [sunrpc] ctrliq#8 [ffff9203ca3237b8] __rpc_execute at ffffffffc041e1c9 [sunrpc] ctrliq#9 [ffff9203ca323820] rpc_execute at ffffffffc0420a48 [sunrpc] The scenario is like this. Let's say there are two upcalls for services A and B, A -> B in pipe->in_downcall, B -> A in pipe->pipe. When rpc.gssd reads pipe to get the upcall msg corresponding to service B from pipe->pipe and then writes the response, in gss_pipe_downcall the msg corresponding to service A will be picked because only uid is used to find the msg and it is before the one for B in pipe->in_downcall. And the process waiting for the msg corresponding to service A will be woken up. Actual scheduing of that process might be after rpc.gssd processes the next msg. In rpc_pipe_generic_upcall it clears msg->errno (for A). The process is scheduled to see gss_msg->ctx == NULL and gss_msg->msg.errno == 0, therefore it cannot break the loop in gss_create_upcall and is never woken up after that. This patch adds a simple check to ensure that a msg which is not sent to rpc.gssd yet is not chosen as the matching upcall upon receiving a downcall. Signed-off-by: minoura makoto <[email protected]> Signed-off-by: Hiroshi Shimamoto <[email protected]> Tested-by: Hiroshi Shimamoto <[email protected]> Cc: Trond Myklebust <[email protected]> Fixes: 9130b8d ("SUNRPC: allow for upcalls for same uid but different gss service") Signed-off-by: Trond Myklebust <[email protected]> (cherry picked from commit b18cba0) Signed-off-by: Jonathan Maple <[email protected]>
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jira LE-1907 Rebuild_History Non-Buildable kernel-rt-5.14.0-284.30.1.rt14.315.el9_2 commit-author Stefan Assmann <[email protected]> commit 4e264be When a system with E810 with existing VFs gets rebooted the following hang may be observed. Pid 1 is hung in iavf_remove(), part of a network driver: PID: 1 TASK: ffff965400e5a340 CPU: 24 COMMAND: "systemd-shutdow" #0 [ffffaad04005fa50] __schedule at ffffffff8b3239cb ctrliq#1 [ffffaad04005fae8] schedule at ffffffff8b323e2d ctrliq#2 [ffffaad04005fb00] schedule_hrtimeout_range_clock at ffffffff8b32cebc ctrliq#3 [ffffaad04005fb80] usleep_range_state at ffffffff8b32c930 ctrliq#4 [ffffaad04005fbb0] iavf_remove at ffffffffc12b9b4c [iavf] ctrliq#5 [ffffaad04005fbf0] pci_device_remove at ffffffff8add7513 ctrliq#6 [ffffaad04005fc10] device_release_driver_internal at ffffffff8af08baa ctrliq#7 [ffffaad04005fc40] pci_stop_bus_device at ffffffff8adcc5fc ctrliq#8 [ffffaad04005fc60] pci_stop_and_remove_bus_device at ffffffff8adcc81e ctrliq#9 [ffffaad04005fc70] pci_iov_remove_virtfn at ffffffff8adf9429 ctrliq#10 [ffffaad04005fca8] sriov_disable at ffffffff8adf98e4 ctrliq#11 [ffffaad04005fcc8] ice_free_vfs at ffffffffc04bb2c8 [ice] ctrliq#12 [ffffaad04005fd10] ice_remove at ffffffffc04778fe [ice] ctrliq#13 [ffffaad04005fd38] ice_shutdown at ffffffffc0477946 [ice] ctrliq#14 [ffffaad04005fd50] pci_device_shutdown at ffffffff8add58f1 ctrliq#15 [ffffaad04005fd70] device_shutdown at ffffffff8af05386 ctrliq#16 [ffffaad04005fd98] kernel_restart at ffffffff8a92a870 ctrliq#17 [ffffaad04005fda8] __do_sys_reboot at ffffffff8a92abd6 ctrliq#18 [ffffaad04005fee0] do_syscall_64 at ffffffff8b317159 ctrliq#19 [ffffaad04005ff08] __context_tracking_enter at ffffffff8b31b6fc ctrliq#20 [ffffaad04005ff18] syscall_exit_to_user_mode at ffffffff8b31b50d ctrliq#21 [ffffaad04005ff28] do_syscall_64 at ffffffff8b317169 ctrliq#22 [ffffaad04005ff50] entry_SYSCALL_64_after_hwframe at ffffffff8b40009b RIP: 00007f1baa5c13d7 RSP: 00007fffbcc55a98 RFLAGS: 00000202 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1baa5c13d7 RDX: 0000000001234567 RSI: 0000000028121969 RDI: 00000000fee1dead RBP: 00007fffbcc55ca0 R8: 0000000000000000 R9: 00007fffbcc54e90 R10: 00007fffbcc55050 R11: 0000000000000202 R12: 0000000000000005 R13: 0000000000000000 R14: 00007fffbcc55af0 R15: 0000000000000000 ORIG_RAX: 00000000000000a9 CS: 0033 SS: 002b During reboot all drivers PM shutdown callbacks are invoked. In iavf_shutdown() the adapter state is changed to __IAVF_REMOVE. In ice_shutdown() the call chain above is executed, which at some point calls iavf_remove(). However iavf_remove() expects the VF to be in one of the states __IAVF_RUNNING, __IAVF_DOWN or __IAVF_INIT_FAILED. If that's not the case it sleeps forever. So if iavf_shutdown() gets invoked before iavf_remove() the system will hang indefinitely because the adapter is already in state __IAVF_REMOVE. Fix this by returning from iavf_remove() if the state is __IAVF_REMOVE, as we already went through iavf_shutdown(). Fixes: 9745780 ("iavf: Add waiting so the port is initialized in remove") Fixes: a841733 ("iavf: Fix race condition between iavf_shutdown and iavf_remove") Reported-by: Marius Cornea <[email protected]> Signed-off-by: Stefan Assmann <[email protected]> Reviewed-by: Michal Kubiak <[email protected]> Tested-by: Rafal Romanowski <[email protected]> Signed-off-by: Tony Nguyen <[email protected]> (cherry picked from commit 4e264be) Signed-off-by: Jonathan Maple <[email protected]>
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jira LE-1907 Rebuild_History Non-Buildable kernel-rt-5.14.0-284.30.1.rt14.315.el9_2 commit-author Michael Ellerman <[email protected]> commit 6d65028 As reported by Alan, the CFI (Call Frame Information) in the VDSO time routines is incorrect since commit ce7d805 ("powerpc/vdso: Prepare for switching VDSO to generic C implementation."). DWARF has a concept called the CFA (Canonical Frame Address), which on powerpc is calculated as an offset from the stack pointer (r1). That means when the stack pointer is changed there must be a corresponding CFI directive to update the calculation of the CFA. The current code is missing those directives for the changes to r1, which prevents gdb from being able to generate a backtrace from inside VDSO functions, eg: Breakpoint 1, 0x00007ffff7f804dc in __kernel_clock_gettime () (gdb) bt #0 0x00007ffff7f804dc in __kernel_clock_gettime () ctrliq#1 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 ctrliq#2 0x00007fffffffd960 in ?? () ctrliq#3 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 Backtrace stopped: frame did not save the PC Alan helpfully describes some rules for correctly maintaining the CFI information: 1) Every adjustment to the current frame address reg (ie. r1) must be described, and exactly at the instruction where r1 changes. Why? Because stack unwinding might want to access previous frames. 2) If a function changes LR or any non-volatile register, the save location for those regs must be given. The CFI can be at any instruction after the saves up to the point that the reg is changed. (Exception: LR save should be described before a bl. not after) 3) If asychronous unwind info is needed then restores of LR and non-volatile regs must also be described. The CFI can be at any instruction after the reg is restored up to the point where the save location is (potentially) trashed. Fix the inability to backtrace by adding CFI directives describing the changes to r1, ie. satisfying rule 1. Also change the information for LR to point to the copy saved on the stack, not the value in r0 that will be overwritten by the function call. Finally, add CFI directives describing the save/restore of r2. With the fix gdb can correctly back trace and navigate up and down the stack: Breakpoint 1, 0x00007ffff7f804dc in __kernel_clock_gettime () (gdb) bt #0 0x00007ffff7f804dc in __kernel_clock_gettime () ctrliq#1 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 ctrliq#2 0x0000000100015b60 in gettime () ctrliq#3 0x000000010000c8bc in print_long_format () ctrliq#4 0x000000010000d180 in print_current_files () ctrliq#5 0x00000001000054ac in main () (gdb) up ctrliq#1 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 (gdb) ctrliq#2 0x0000000100015b60 in gettime () (gdb) ctrliq#3 0x000000010000c8bc in print_long_format () (gdb) ctrliq#4 0x000000010000d180 in print_current_files () (gdb) ctrliq#5 0x00000001000054ac in main () (gdb) Initial frame selected; you cannot go up. (gdb) down ctrliq#4 0x000000010000d180 in print_current_files () (gdb) ctrliq#3 0x000000010000c8bc in print_long_format () (gdb) ctrliq#2 0x0000000100015b60 in gettime () (gdb) ctrliq#1 0x00007ffff7d8872c in clock_gettime@@GLIBC_2.17 () from /lib64/libc.so.6 (gdb) #0 0x00007ffff7f804dc in __kernel_clock_gettime () (gdb) Fixes: ce7d805 ("powerpc/vdso: Prepare for switching VDSO to generic C implementation.") Cc: [email protected] # v5.11+ Reported-by: Alan Modra <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Reviewed-by: Segher Boessenkool <[email protected]> Link: https://lore.kernel.org/r/[email protected] (cherry picked from commit 6d65028) Signed-off-by: Jonathan Maple <[email protected]>
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jira LE-1907 Rebuild_History Non-Buildable kernel-rt-5.14.0-284.30.1.rt14.315.el9_2 commit-author Eelco Chaudron <[email protected]> commit de9df6c Currently, the per cpu upcall counters are allocated after the vport is created and inserted into the system. This could lead to the datapath accessing the counters before they are allocated resulting in a kernel Oops. Here is an example: PID: 59693 TASK: ffff0005f4f51500 CPU: 0 COMMAND: "ovs-vswitchd" #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4 ctrliq#1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc ctrliq#2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60 ctrliq#3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58 ctrliq#4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388 ctrliq#5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c ctrliq#6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68 ctrliq#7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch] ... PID: 58682 TASK: ffff0005b2f0bf00 CPU: 0 COMMAND: "kworker/0:3" #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758 ctrliq#1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994 ctrliq#2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8 ctrliq#3 [ffff80000a5d3120] die at ffffb70f0628234c ctrliq#4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8 ctrliq#5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4 ctrliq#6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4 ctrliq#7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710 ctrliq#8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74 ctrliq#9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac ctrliq#10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24 ctrliq#11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc ctrliq#12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch] ctrliq#13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch] ctrliq#14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch] ctrliq#15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch] ctrliq#16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch] ctrliq#17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90 We moved the per cpu upcall counter allocation to the existing vport alloc and free functions to solve this. Fixes: 95637d9 ("net: openvswitch: release vport resources on failure") Fixes: 1933ea3 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: Eelco Chaudron <[email protected]> Reviewed-by: Simon Horman <[email protected]> Acked-by: Aaron Conole <[email protected]> Signed-off-by: David S. Miller <[email protected]> (cherry picked from commit de9df6c) Signed-off-by: Jonathan Maple <[email protected]>
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…rary mm [ Upstream commit dc9c516 ] Erhard reports the following KASAN hit on Talos II (power9) with kernel 6.13: [ 12.028126] ================================================================== [ 12.028198] BUG: KASAN: user-memory-access in copy_to_kernel_nofault+0x8c/0x1a0 [ 12.028260] Write of size 8 at addr 0000187e458f2000 by task systemd/1 [ 12.028346] CPU: 87 UID: 0 PID: 1 Comm: systemd Tainted: G T 6.13.0-P9-dirty #3 [ 12.028408] Tainted: [T]=RANDSTRUCT [ 12.028446] Hardware name: T2P9D01 REV 1.01 POWER9 0x4e1202 opal:skiboot-bc106a0 PowerNV [ 12.028500] Call Trace: [ 12.028536] [c000000008dbf3b0] [c000000001656a48] dump_stack_lvl+0xbc/0x110 (unreliable) [ 12.028609] [c000000008dbf3f0] [c0000000006e2fc8] print_report+0x6b0/0x708 [ 12.028666] [c000000008dbf4e0] [c0000000006e2454] kasan_report+0x164/0x300 [ 12.028725] [c000000008dbf600] [c0000000006e54d4] kasan_check_range+0x314/0x370 [ 12.028784] [c000000008dbf640] [c0000000006e6310] __kasan_check_write+0x20/0x40 [ 12.028842] [c000000008dbf660] [c000000000578e8c] copy_to_kernel_nofault+0x8c/0x1a0 [ 12.028902] [c000000008dbf6a0] [c0000000000acfe4] __patch_instructions+0x194/0x210 [ 12.028965] [c000000008dbf6e0] [c0000000000ade80] patch_instructions+0x150/0x590 [ 12.029026] [c000000008dbf7c0] [c0000000001159bc] bpf_arch_text_copy+0x6c/0xe0 [ 12.029085] [c000000008dbf800] [c000000000424250] bpf_jit_binary_pack_finalize+0x40/0xc0 [ 12.029147] [c000000008dbf830] [c000000000115dec] bpf_int_jit_compile+0x3bc/0x930 [ 12.029206] [c000000008dbf990] [c000000000423720] bpf_prog_select_runtime+0x1f0/0x280 [ 12.029266] [c000000008dbfa00] [c000000000434b18] bpf_prog_load+0xbb8/0x1370 [ 12.029324] [c000000008dbfb70] [c000000000436ebc] __sys_bpf+0x5ac/0x2e00 [ 12.029379] [c000000008dbfd00] [c00000000043a228] sys_bpf+0x28/0x40 [ 12.029435] [c000000008dbfd20] [c000000000038eb4] system_call_exception+0x334/0x610 [ 12.029497] [c000000008dbfe50] [c00000000000c270] system_call_vectored_common+0xf0/0x280 [ 12.029561] --- interrupt: 3000 at 0x3fff82f5cfa8 [ 12.029608] NIP: 00003fff82f5cfa8 LR: 00003fff82f5cfa8 CTR: 0000000000000000 [ 12.029660] REGS: c000000008dbfe80 TRAP: 3000 Tainted: G T (6.13.0-P9-dirty) [ 12.029735] MSR: 900000000280f032 <SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI> CR: 42004848 XER: 00000000 [ 12.029855] IRQMASK: 0 GPR00: 0000000000000169 00003fffdcf789a0 00003fff83067100 0000000000000005 GPR04: 00003fffdcf78a98 0000000000000090 0000000000000000 0000000000000008 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 0000000000000000 00003fff836ff7e0 c000000000010678 0000000000000000 GPR16: 0000000000000000 0000000000000000 00003fffdcf78f28 00003fffdcf78f90 GPR20: 0000000000000000 0000000000000000 0000000000000000 00003fffdcf78f80 GPR24: 00003fffdcf78f70 00003fffdcf78d10 00003fff835c7239 00003fffdcf78bd8 GPR28: 00003fffdcf78a98 0000000000000000 0000000000000000 000000011f547580 [ 12.030316] NIP [00003fff82f5cfa8] 0x3fff82f5cfa8 [ 12.030361] LR [00003fff82f5cfa8] 0x3fff82f5cfa8 [ 12.030405] --- interrupt: 3000 [ 12.030444] ================================================================== Commit c28c15b ("powerpc/code-patching: Use temporary mm for Radix MMU") is inspired from x86 but unlike x86 is doesn't disable KASAN reports during patching. This wasn't a problem at the begining because __patch_mem() is not instrumented. Commit 465cabc ("powerpc/code-patching: introduce patch_instructions()") use copy_to_kernel_nofault() to copy several instructions at once. But when using temporary mm the destination is not regular kernel memory but a kind of kernel-like memory located in user address space. Because it is not in kernel address space it is not covered by KASAN shadow memory. Since commit e4137f0 ("mm, kasan, kmsan: instrument copy_from/to_kernel_nofault") KASAN reports bad accesses from copy_to_kernel_nofault(). Here a bad access to user memory is reported because KASAN detects the lack of shadow memory and the address is below TASK_SIZE. Do like x86 in commit b3fd8e8 ("x86/alternatives: Use temporary mm for text poking") and disable KASAN reports during patching when using temporary mm. Reported-by: Erhard Furtner <[email protected]> Close: https://lore.kernel.org/all/20250201151435.48400261@yea/ Fixes: 465cabc ("powerpc/code-patching: introduce patch_instructions()") Signed-off-by: Christophe Leroy <[email protected]> Acked-by: Michael Ellerman <[email protected]> Signed-off-by: Madhavan Srinivasan <[email protected]> Link: https://patch.msgid.link/1c05b2a1b02ad75b981cfc45927e0b4a90441046.1738577687.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin <[email protected]>
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commit f02c41f upstream. Use raw_spinlock in order to fix spurious messages about invalid context when spinlock debugging is enabled. The lock is only used to serialize register access. [ 4.239592] ============================= [ 4.239595] [ BUG: Invalid wait context ] [ 4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35 Not tainted [ 4.239603] ----------------------------- [ 4.239606] kworker/u8:5/76 is trying to lock: [ 4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164 [ 4.239641] other info that might help us debug this: [ 4.239643] context-{5:5} [ 4.239646] 5 locks held by kworker/u8:5/76: [ 4.239651] #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c [ 4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value. [ 4.254094] #1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c [ 4.254109] #2: ffff00000920c8f8 [ 4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value. [ 4.264803] (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc [ 4.264820] #3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690 [ 4.264840] #4: [ 4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value. [ 4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690 [ 4.296130] renesas_sdhi_internal_dmac ee100000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz [ 4.304082] stack backtrace: [ 4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35 [ 4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT) [ 4.304097] Workqueue: async async_run_entry_fn [ 4.304106] Call trace: [ 4.304110] show_stack+0x14/0x20 (C) [ 4.304122] dump_stack_lvl+0x6c/0x90 [ 4.304131] dump_stack+0x14/0x1c [ 4.304138] __lock_acquire+0xdfc/0x1584 [ 4.426274] lock_acquire+0x1c4/0x33c [ 4.429942] _raw_spin_lock_irqsave+0x5c/0x80 [ 4.434307] gpio_rcar_config_interrupt_input_mode+0x34/0x164 [ 4.440061] gpio_rcar_irq_set_type+0xd4/0xd8 [ 4.444422] __irq_set_trigger+0x5c/0x178 [ 4.448435] __setup_irq+0x2e4/0x690 [ 4.452012] request_threaded_irq+0xc4/0x190 [ 4.456285] devm_request_threaded_irq+0x7c/0xf4 [ 4.459398] ata1: link resume succeeded after 1 retries [ 4.460902] mmc_gpiod_request_cd_irq+0x68/0xe0 [ 4.470660] mmc_start_host+0x50/0xac [ 4.474327] mmc_add_host+0x80/0xe4 [ 4.477817] tmio_mmc_host_probe+0x2b0/0x440 [ 4.482094] renesas_sdhi_probe+0x488/0x6f4 [ 4.486281] renesas_sdhi_internal_dmac_probe+0x60/0x78 [ 4.491509] platform_probe+0x64/0xd8 [ 4.495178] really_probe+0xb8/0x2a8 [ 4.498756] __driver_probe_device+0x74/0x118 [ 4.503116] driver_probe_device+0x3c/0x154 [ 4.507303] __device_attach_driver+0xd4/0x160 [ 4.511750] bus_for_each_drv+0x84/0xe0 [ 4.515588] __device_attach_async_helper+0xb0/0xdc [ 4.520470] async_run_entry_fn+0x30/0xd8 [ 4.524481] process_one_work+0x210/0x62c [ 4.528494] worker_thread+0x1ac/0x340 [ 4.532245] kthread+0x10c/0x110 [ 4.535476] ret_from_fork+0x10/0x20 Signed-off-by: Niklas Söderlund <[email protected]> Reviewed-by: Geert Uytterhoeven <[email protected]> Tested-by: Geert Uytterhoeven <[email protected]> Cc: [email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Bartosz Golaszewski <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit 9f7b2aa ] When mb-xdp is set and return is XDP_PASS, packet is converted from xdp_buff to sk_buff with xdp_update_skb_shared_info() in bnxt_xdp_build_skb(). bnxt_xdp_build_skb() passes incorrect truesize argument to xdp_update_skb_shared_info(). The truesize is calculated as BNXT_RX_PAGE_SIZE * sinfo->nr_frags but the skb_shared_info was wiped by napi_build_skb() before. So it stores sinfo->nr_frags before bnxt_xdp_build_skb() and use it instead of getting skb_shared_info from xdp_get_shared_info_from_buff(). Splat looks like: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 0 at net/core/skbuff.c:6072 skb_try_coalesce+0x504/0x590 Modules linked in: xt_nat xt_tcpudp veth af_packet xt_conntrack nft_chain_nat xt_MASQUERADE nf_conntrack_netlink xfrm_user xt_addrtype nft_coms CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.14.0-rc2+ #3 RIP: 0010:skb_try_coalesce+0x504/0x590 Code: 4b fd ff ff 49 8b 34 24 40 80 e6 40 0f 84 3d fd ff ff 49 8b 74 24 48 40 f6 c6 01 0f 84 2e fd ff ff 48 8d 4e ff e9 25 fd ff ff <0f> 0b e99 RSP: 0018:ffffb62c4120caa8 EFLAGS: 00010287 RAX: 0000000000000003 RBX: ffffb62c4120cb14 RCX: 0000000000000ec0 RDX: 0000000000001000 RSI: ffffa06e5d7dc000 RDI: 0000000000000003 RBP: ffffa06e5d7ddec0 R08: ffffa06e6120a800 R09: ffffa06e7a119900 R10: 0000000000002310 R11: ffffa06e5d7dcec0 R12: ffffe4360575f740 R13: ffffe43600000000 R14: 0000000000000002 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffffa0755f700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f147b76b0f8 CR3: 00000001615d4000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <IRQ> ? __warn+0x84/0x130 ? skb_try_coalesce+0x504/0x590 ? report_bug+0x18a/0x1a0 ? handle_bug+0x53/0x90 ? exc_invalid_op+0x14/0x70 ? asm_exc_invalid_op+0x16/0x20 ? skb_try_coalesce+0x504/0x590 inet_frag_reasm_finish+0x11f/0x2e0 ip_defrag+0x37a/0x900 ip_local_deliver+0x51/0x120 ip_sublist_rcv_finish+0x64/0x70 ip_sublist_rcv+0x179/0x210 ip_list_rcv+0xf9/0x130 How to reproduce: <Node A> ip link set $interface1 xdp obj xdp_pass.o ip link set $interface1 mtu 9000 up ip a a 10.0.0.1/24 dev $interface1 <Node B> ip link set $interfac2 mtu 9000 up ip a a 10.0.0.2/24 dev $interface2 ping 10.0.0.1 -s 65000 Following ping.py patch adds xdp-mb-pass case. so ping.py is going to be able to reproduce this issue. Fixes: 1dc4c55 ("bnxt: adding bnxt_xdp_build_skb to build skb from multibuffer xdp_buff") Signed-off-by: Taehee Yoo <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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Patch series "Fix calculations in trace_balance_dirty_pages() for cgwb", v2. In my experiment, I found that the output of trace_balance_dirty_pages() in the cgroup writeback scenario was strange because trace_balance_dirty_pages() always uses global_wb_domain.dirty_limit for related calculations instead of the dirty_limit of the corresponding memcg's wb_domain. The basic idea of the fix is to store the hard dirty limit value computed in wb_position_ratio() into struct dirty_throttle_control and use it for calculations in trace_balance_dirty_pages(). This patch (of 3): Currently, trace_balance_dirty_pages() already has 12 parameters. In the patch #3, I initially attempted to introduce an additional parameter. However, in include/linux/trace_events.h, bpf_trace_run12() only supports up to 12 parameters and bpf_trace_run13() does not exist. To reduce the number of parameters in trace_balance_dirty_pages(), we can make it accept a pointer to struct dirty_throttle_control as a parameter. To achieve this, we need to move the definition of struct dirty_throttle_control from mm/page-writeback.c to include/linux/writeback.h. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Tang Yizhou <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: Christian Brauner <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Jan Kara <[email protected]> Cc: "Masami Hiramatsu (Google)" <[email protected]> Cc: Matthew Wilcow (Oracle) <[email protected]> Cc: Tang Yizhou <[email protected]> Cc: Tejun Heo <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
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Patch series "mm: page_ext: Introduce new iteration API", v3.
Introduction
============
[ Thanks to David Hildenbrand for identifying the root cause of this
issue and proving guidance on how to fix it. The new API idea, bugs
and misconceptions are all mine though ]
Currently, trying to reserve 1G pages with page_owner=on and sparsemem
causes a crash. The reproducer is very simple:
1. Build the kernel with CONFIG_SPARSEMEM=y and the table extensions
2. Pass 'default_hugepagesz=1 page_owner=on' in the kernel command-line
3. Reserve one 1G page at run-time, this should crash (see patch 1 for
backtrace)
[ A crash with page_table_check is also possible, but harder to trigger ]
Apparently, starting with commit cf54f31 ("mm/hugetlb: use __GFP_COMP
for gigantic folios") we now pass the full allocation order to page
extension clients and the page extension implementation assumes that all
PFNs of an allocation range will be stored in the same memory section (which
is not true for 1G pages).
To fix this, this series introduces a new iteration API for page extension
objects. The API checks if the next page extension object can be retrieved
from the current section or if it needs to look up for it in another
section.
Please, find all details in patch 1.
I tested this series on arm64 and x86 by reserving 1G pages at run-time
and doing kernel builds (always with page_owner=on and page_table_check=on).
This patch (of 3):
The page extension implementation assumes that all page extensions of a
given page order are stored in the same memory section. The function
page_ext_next() relies on this assumption by adding an offset to the
current object to return the next adjacent page extension.
This behavior works as expected for flatmem but fails for sparsemem when
using 1G pages. The commit cf54f31 ("mm/hugetlb: use __GFP_COMP for
gigantic folios") exposes this issue, making it possible for a crash when
using page_owner or page_table_check page extensions.
The problem is that for 1G pages, the page extensions may span memory
section boundaries and be stored in different memory sections. This issue
was not visible before commit cf54f31 ("mm/hugetlb: use __GFP_COMP
for gigantic folios") because alloc_contig_pages() never passed more than
MAX_PAGE_ORDER to post_alloc_hook(). However, the series introducing
mentioned commit changed this behavior allowing the full 1G page order to
be passed.
Reproducer:
1. Build the kernel with CONFIG_SPARSEMEM=y and table extensions
support
2. Pass 'default_hugepagesz=1 page_owner=on' in the kernel command-line
3. Reserve one 1G page at run-time, this should crash (backtrace below)
To address this issue, this commit introduces a new API for iterating
through page extensions. The main iteration macro is for_each_page_ext()
and it must be called with the RCU read lock taken. Here's an usage
example:
"""
struct page_ext_iter iter;
struct page_ext *page_ext;
...
rcu_read_lock();
for_each_page_ext(page, 1 << order, page_ext, iter) {
struct my_page_ext *obj = get_my_page_ext_obj(page_ext);
...
}
rcu_read_unlock();
"""
The loop construct uses page_ext_iter_next() which checks to see if we
have crossed sections in the iteration. In this case,
page_ext_iter_next() retrieves the next page_ext object from another
section.
Thanks to David Hildenbrand for helping identify the root cause and
providing suggestions on how to fix and optmize the solution (final
implementation and bugs are all mine through).
Lastly, here's the backtrace, without kasan you can get random crashes:
[ 76.052526] BUG: KASAN: slab-out-of-bounds in __update_page_owner_handle+0x238/0x298
[ 76.060283] Write of size 4 at addr ffff07ff96240038 by task tee/3598
[ 76.066714]
[ 76.068203] CPU: 88 UID: 0 PID: 3598 Comm: tee Kdump: loaded Not tainted 6.13.0-rep1 #3
[ 76.076202] Hardware name: WIWYNN Mt.Jade Server System B81.030Z1.0007/Mt.Jade Motherboard, BIOS 2.10.20220810 (SCP: 2.10.20220810) 2022/08/10
[ 76.088972] Call trace:
[ 76.091411] show_stack+0x20/0x38 (C)
[ 76.095073] dump_stack_lvl+0x80/0xf8
[ 76.098733] print_address_description.constprop.0+0x88/0x398
[ 76.104476] print_report+0xa8/0x278
[ 76.108041] kasan_report+0xa8/0xf8
[ 76.111520] __asan_report_store4_noabort+0x20/0x30
[ 76.116391] __update_page_owner_handle+0x238/0x298
[ 76.121259] __set_page_owner+0xdc/0x140
[ 76.125173] post_alloc_hook+0x190/0x1d8
[ 76.129090] alloc_contig_range_noprof+0x54c/0x890
[ 76.133874] alloc_contig_pages_noprof+0x35c/0x4a8
[ 76.138656] alloc_gigantic_folio.isra.0+0x2c0/0x368
[ 76.143616] only_alloc_fresh_hugetlb_folio.isra.0+0x24/0x150
[ 76.149353] alloc_pool_huge_folio+0x11c/0x1f8
[ 76.153787] set_max_huge_pages+0x364/0xca8
[ 76.157961] __nr_hugepages_store_common+0xb0/0x1a0
[ 76.162829] nr_hugepages_store+0x108/0x118
[ 76.167003] kobj_attr_store+0x3c/0x70
[ 76.170745] sysfs_kf_write+0xfc/0x188
[ 76.174492] kernfs_fop_write_iter+0x274/0x3e0
[ 76.178927] vfs_write+0x64c/0x8e0
[ 76.182323] ksys_write+0xf8/0x1f0
[ 76.185716] __arm64_sys_write+0x74/0xb0
[ 76.189630] invoke_syscall.constprop.0+0xd8/0x1e0
[ 76.194412] do_el0_svc+0x164/0x1e0
[ 76.197891] el0_svc+0x40/0xe0
[ 76.200939] el0t_64_sync_handler+0x144/0x168
[ 76.205287] el0t_64_sync+0x1ac/0x1b0
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/a45893880b7e1601082d39d2c5c8b50bcc096305.1741301089.git.luizcap@redhat.com
Fixes: cf54f31 ("mm/hugetlb: use __GFP_COMP for gigantic folios")
Signed-off-by: Luiz Capitulino <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Luiz Capitulino <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Pasha Tatashin <[email protected]>
Cc: Yu Zhao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
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Syzkaller reports a bug as follows: Injecting memory failure for pfn 0x18b00e at process virtual address 0x20ffd000 Memory failure: 0x18b00e: dirty swapcache page still referenced by 2 users Memory failure: 0x18b00e: recovery action for dirty swapcache page: Failed page: refcount:2 mapcount:0 mapping:0000000000000000 index:0x20ffd pfn:0x18b00e memcg:ffff0000dd6d9000 anon flags: 0x5ffffe00482011(locked|dirty|arch_1|swapbacked|hwpoison|node=0|zone=2|lastcpupid=0xfffff) raw: 005ffffe00482011 dead000000000100 dead000000000122 ffff0000e232a7c9 raw: 0000000000020ffd 0000000000000000 00000002ffffffff ffff0000dd6d9000 page dumped because: VM_BUG_ON_FOLIO(!folio_test_uptodate(folio)) ------------[ cut here ]------------ kernel BUG at mm/swap_state.c:184! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Modules linked in: CPU: 0 PID: 60 Comm: kswapd0 Not tainted 6.6.0-gcb097e7de84e #3 Hardware name: linux,dummy-virt (DT) pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : add_to_swap+0xbc/0x158 lr : add_to_swap+0xbc/0x158 sp : ffff800087f37340 x29: ffff800087f37340 x28: fffffc00052c0380 x27: ffff800087f37780 x26: ffff800087f37490 x25: ffff800087f37c78 x24: ffff800087f377a0 x23: ffff800087f37c50 x22: 0000000000000000 x21: fffffc00052c03b4 x20: 0000000000000000 x19: fffffc00052c0380 x18: 0000000000000000 x17: 296f696c6f662865 x16: 7461646f7470755f x15: 747365745f6f696c x14: 6f6621284f494c4f x13: 0000000000000001 x12: ffff600036d8b97b x11: 1fffe00036d8b97a x10: ffff600036d8b97a x9 : dfff800000000000 x8 : 00009fffc9274686 x7 : ffff0001b6c5cbd3 x6 : 0000000000000001 x5 : ffff0000c25896c0 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : ffff0000c25896c0 x0 : 0000000000000000 Call trace: add_to_swap+0xbc/0x158 shrink_folio_list+0x12ac/0x2648 shrink_inactive_list+0x318/0x948 shrink_lruvec+0x450/0x720 shrink_node_memcgs+0x280/0x4a8 shrink_node+0x128/0x978 balance_pgdat+0x4f0/0xb20 kswapd+0x228/0x438 kthread+0x214/0x230 ret_from_fork+0x10/0x20 I can reproduce this issue with the following steps: 1) When a dirty swapcache page is isolated by reclaim process and the page isn't locked, inject memory failure for the page. me_swapcache_dirty() clears uptodate flag and tries to delete from lru, but fails. Reclaim process will put the hwpoisoned page back to lru. 2) The process that maps the hwpoisoned page exits, the page is deleted the page will never be freed and will be in the lru forever. 3) If we trigger a reclaim again and tries to reclaim the page, add_to_swap() will trigger VM_BUG_ON_FOLIO due to the uptodate flag is cleared. To fix it, skip the hwpoisoned page in shrink_folio_list(). Besides, the hwpoison folio may not be unmapped by hwpoison_user_mappings() yet, unmap it in shrink_folio_list(), otherwise the folio will fail to be unmaped by hwpoison_user_mappings() since the folio isn't in lru list. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Jinjiang Tu <[email protected]> Acked-by: Miaohe Lin <[email protected]> Cc: David Hildenbrand <[email protected]> Cc: Kefeng Wang <[email protected]> Cc: Nanyong Sun <[email protected]> Cc: Naoya Horiguchi <[email protected]> Cc: <stable@vger,kernel.org> Signed-off-by: Andrew Morton <[email protected]>
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Two fixes from the recent logging changes:
bch2_inconsistent(), bch2_fs_inconsistent() be called from interrupt
context, or with rcu_read_lock() held.
The one syzbot found is in
bch2_bkey_pick_read_device
bch2_dev_rcu
bch2_fs_inconsistent
We're starting to switch to lift the printbufs up to higher levels so we
can emit better log messages and print them all in one go (avoid
garbling), so that conversion will help with spotting these in the
future; when we declare a printbuf it must be flagged if we're in an
atomic context.
Secondly, in btree_node_write_endio:
00085 BUG: sleeping function called from invalid context at include/linux/sched/mm.h:321
00085 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 618, name: bch-reclaim/fa6
00085 preempt_count: 10001, expected: 0
00085 RCU nest depth: 0, expected: 0
00085 4 locks held by bch-reclaim/fa6/618:
00085 #0: ffffff80d7ccad68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x84/0x198
00085 #1: ffffff80d7c84218 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x1c0/0x440
00085 #2: ffffff80cd3f8140 (bcachefs_btree){+.+.}-{0:0}, at: __bch2_trans_get+0x22c/0x440
00085 #3: ffffff80c3823c20 (&vblk->vqs[i].lock){-.-.}-{3:3}, at: virtblk_done+0x58/0x130
00085 irq event stamp: 328
00085 hardirqs last enabled at (327): [<ffffffc080073a14>] finish_task_switch.isra.0+0xbc/0x2a0
00085 hardirqs last disabled at (328): [<ffffffc080971a10>] el1_interrupt+0x20/0x60
00085 softirqs last enabled at (0): [<ffffffc08002f920>] copy_process+0x7c8/0x2118
00085 softirqs last disabled at (0): [<0000000000000000>] 0x0
00085 Preemption disabled at:
00085 [<ffffffc08003ada0>] irq_enter_rcu+0x18/0x90
00085 CPU: 8 UID: 0 PID: 618 Comm: bch-reclaim/fa6 Not tainted 6.14.0-rc6-ktest-g04630bde23e8 #18798
00085 Hardware name: linux,dummy-virt (DT)
00085 Call trace:
00085 show_stack+0x1c/0x30 (C)
00085 dump_stack_lvl+0x84/0xc0
00085 dump_stack+0x14/0x20
00085 __might_resched+0x180/0x288
00085 __might_sleep+0x4c/0x88
00085 __kmalloc_node_track_caller_noprof+0x34c/0x3e0
00085 krealloc_noprof+0x1a0/0x2d8
00085 bch2_printbuf_make_room+0x9c/0x120
00085 bch2_prt_printf+0x60/0x1b8
00085 btree_node_write_endio+0x1b0/0x2d8
00085 bio_endio+0x138/0x1f0
00085 btree_node_write_endio+0xe8/0x2d8
00085 bio_endio+0x138/0x1f0
00085 blk_update_request+0x220/0x4c0
00085 blk_mq_end_request+0x28/0x148
00085 virtblk_request_done+0x64/0xe8
00085 blk_mq_complete_request+0x34/0x40
00085 virtblk_done+0x78/0x130
00085 vring_interrupt+0x6c/0xb0
00085 __handle_irq_event_percpu+0x8c/0x2e0
00085 handle_irq_event+0x50/0xb0
00085 handle_fasteoi_irq+0xc4/0x250
00085 handle_irq_desc+0x44/0x60
00085 generic_handle_domain_irq+0x20/0x30
00085 gic_handle_irq+0x54/0xc8
00085 call_on_irq_stack+0x24/0x40
Reported-by: [email protected]
Signed-off-by: Kent Overstreet <[email protected]>
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v2:
- Created a single error handling unlock and exit in veth_pool_store
- Greatly expanded commit message with previous explanatory-only text
Summary: Use rtnl_mutex to synchronize veth_pool_store with itself,
ibmveth_close and ibmveth_open, preventing multiple calls in a row to
napi_disable.
Background: Two (or more) threads could call veth_pool_store through
writing to /sys/devices/vio/30000002/pool*/*. You can do this easily
with a little shell script. This causes a hang.
I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new
kernel. I ran this test again and saw:
Setting pool0/active to 0
Setting pool1/active to 1
[ 73.911067][ T4365] ibmveth 30000002 eth0: close starting
Setting pool1/active to 1
Setting pool1/active to 0
[ 73.911367][ T4366] ibmveth 30000002 eth0: close starting
[ 73.916056][ T4365] ibmveth 30000002 eth0: close complete
[ 73.916064][ T4365] ibmveth 30000002 eth0: open starting
[ 110.808564][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
[ 230.808495][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification.
[ 243.683786][ T123] INFO: task stress.sh:4365 blocked for more than 122 seconds.
[ 243.683827][ T123] Not tainted 6.14.0-01103-g2df0c02dab82-dirty ctrliq#8
[ 243.683833][ T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 243.683838][ T123] task:stress.sh state:D stack:28096 pid:4365 tgid:4365 ppid:4364 task_flags:0x400040 flags:0x00042000
[ 243.683852][ T123] Call Trace:
[ 243.683857][ T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable)
[ 243.683868][ T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0
[ 243.683878][ T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0
[ 243.683888][ T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210
[ 243.683896][ T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50
[ 243.683904][ T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0
[ 243.683913][ T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60
[ 243.683921][ T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc
[ 243.683928][ T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270
[ 243.683936][ T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0
[ 243.683944][ T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0
[ 243.683951][ T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650
[ 243.683958][ T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150
[ 243.683966][ T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340
[ 243.683973][ T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec
...
[ 243.684087][ T123] Showing all locks held in the system:
[ 243.684095][ T123] 1 lock held by khungtaskd/123:
[ 243.684099][ T123] #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248
[ 243.684114][ T123] 4 locks held by stress.sh/4365:
[ 243.684119][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
[ 243.684132][ T123] #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
[ 243.684143][ T123] #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
[ 243.684155][ T123] #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60
[ 243.684166][ T123] 5 locks held by stress.sh/4366:
[ 243.684170][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150
[ 243.684183][ T123] #1: c00000000aee2288 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0
[ 243.684194][ T123] #2: c0000000366f4ba8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0
[ 243.684205][ T123] #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_disable+0x30/0x60
[ 243.684216][ T123] #4: c0000003ff9bbf18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x138/0x12a0
From the ibmveth debug, two threads are calling veth_pool_store, which
calls ibmveth_close and ibmveth_open. Here's the sequence:
T4365 T4366
----------------- ----------------- ---------
veth_pool_store veth_pool_store
ibmveth_close
ibmveth_close
napi_disable
napi_disable
ibmveth_open
napi_enable <- HANG
ibmveth_close calls napi_disable at the top and ibmveth_open calls
napi_enable at the top.
https://docs.kernel.org/networking/napi.html]] says
The control APIs are not idempotent. Control API calls are safe
against concurrent use of datapath APIs but an incorrect sequence of
control API calls may result in crashes, deadlocks, or race
conditions. For example, calling napi_disable() multiple times in a
row will deadlock.
In the normal open and close paths, rtnl_mutex is acquired to prevent
other callers. This is missing from veth_pool_store. Use rtnl_mutex in
veth_pool_store fixes these hangs.
Signed-off-by: Dave Marquardt <[email protected]>
Fixes: 860f242 ("[PATCH] ibmveth change buffer pools dynamically")
Reviewed-by: Nick Child <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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…le_direct_reclaim() jira LE-2741 Rebuild_History Non-Buildable kernel-4.18.0-553.42.1.el8_10 commit-author Seiji Nishikawa <[email protected]> commit 6aaced5 The task sometimes continues looping in throttle_direct_reclaim() because allow_direct_reclaim(pgdat) keeps returning false. #0 [ffff80002cb6f8d0] __switch_to at ffff8000080095ac #1 [ffff80002cb6f900] __schedule at ffff800008abbd1c #2 [ffff80002cb6f990] schedule at ffff800008abc50c #3 [ffff80002cb6f9b0] throttle_direct_reclaim at ffff800008273550 #4 [ffff80002cb6fa20] try_to_free_pages at ffff800008277b68 #5 [ffff80002cb6fae0] __alloc_pages_nodemask at ffff8000082c4660 #6 [ffff80002cb6fc50] alloc_pages_vma at ffff8000082e4a98 #7 [ffff80002cb6fca0] do_anonymous_page at ffff80000829f5a8 #8 [ffff80002cb6fce0] __handle_mm_fault at ffff8000082a5974 #9 [ffff80002cb6fd90] handle_mm_fault at ffff8000082a5bd4 At this point, the pgdat contains the following two zones: NODE: 4 ZONE: 0 ADDR: ffff00817fffe540 NAME: "DMA32" SIZE: 20480 MIN/LOW/HIGH: 11/28/45 VM_STAT: NR_FREE_PAGES: 359 NR_ZONE_INACTIVE_ANON: 18813 NR_ZONE_ACTIVE_ANON: 0 NR_ZONE_INACTIVE_FILE: 50 NR_ZONE_ACTIVE_FILE: 0 NR_ZONE_UNEVICTABLE: 0 NR_ZONE_WRITE_PENDING: 0 NR_MLOCK: 0 NR_BOUNCE: 0 NR_ZSPAGES: 0 NR_FREE_CMA_PAGES: 0 NODE: 4 ZONE: 1 ADDR: ffff00817fffec00 NAME: "Normal" SIZE: 8454144 PRESENT: 98304 MIN/LOW/HIGH: 68/166/264 VM_STAT: NR_FREE_PAGES: 146 NR_ZONE_INACTIVE_ANON: 94668 NR_ZONE_ACTIVE_ANON: 3 NR_ZONE_INACTIVE_FILE: 735 NR_ZONE_ACTIVE_FILE: 78 NR_ZONE_UNEVICTABLE: 0 NR_ZONE_WRITE_PENDING: 0 NR_MLOCK: 0 NR_BOUNCE: 0 NR_ZSPAGES: 0 NR_FREE_CMA_PAGES: 0 In allow_direct_reclaim(), while processing ZONE_DMA32, the sum of inactive/active file-backed pages calculated in zone_reclaimable_pages() based on the result of zone_page_state_snapshot() is zero. Additionally, since this system lacks swap, the calculation of inactive/ active anonymous pages is skipped. crash> p nr_swap_pages nr_swap_pages = $1937 = { counter = 0 } As a result, ZONE_DMA32 is deemed unreclaimable and skipped, moving on to the processing of the next zone, ZONE_NORMAL, despite ZONE_DMA32 having free pages significantly exceeding the high watermark. The problem is that the pgdat->kswapd_failures hasn't been incremented. crash> px ((struct pglist_data *) 0xffff00817fffe540)->kswapd_failures $1935 = 0x0 This is because the node deemed balanced. The node balancing logic in balance_pgdat() evaluates all zones collectively. If one or more zones (e.g., ZONE_DMA32) have enough free pages to meet their watermarks, the entire node is deemed balanced. This causes balance_pgdat() to exit early before incrementing the kswapd_failures, as it considers the overall memory state acceptable, even though some zones (like ZONE_NORMAL) remain under significant pressure. The patch ensures that zone_reclaimable_pages() includes free pages (NR_FREE_PAGES) in its calculation when no other reclaimable pages are available (e.g., file-backed or anonymous pages). This change prevents zones like ZONE_DMA32, which have sufficient free pages, from being mistakenly deemed unreclaimable. By doing so, the patch ensures proper node balancing, avoids masking pressure on other zones like ZONE_NORMAL, and prevents infinite loops in throttle_direct_reclaim() caused by allow_direct_reclaim(pgdat) repeatedly returning false. The kernel hangs due to a task stuck in throttle_direct_reclaim(), caused by a node being incorrectly deemed balanced despite pressure in certain zones, such as ZONE_NORMAL. This issue arises from zone_reclaimable_pages() returning 0 for zones without reclaimable file- backed or anonymous pages, causing zones like ZONE_DMA32 with sufficient free pages to be skipped. The lack of swap or reclaimable pages results in ZONE_DMA32 being ignored during reclaim, masking pressure in other zones. Consequently, pgdat->kswapd_failures remains 0 in balance_pgdat(), preventing fallback mechanisms in allow_direct_reclaim() from being triggered, leading to an infinite loop in throttle_direct_reclaim(). This patch modifies zone_reclaimable_pages() to account for free pages (NR_FREE_PAGES) when no other reclaimable pages exist. This ensures zones with sufficient free pages are not skipped, enabling proper balancing and reclaim behavior. [[email protected]: coding-style cleanups] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Fixes: 5a1c84b ("mm: remove reclaim and compaction retry approximations") Signed-off-by: Seiji Nishikawa <[email protected]> Cc: Mel Gorman <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> (cherry picked from commit 6aaced5) Signed-off-by: Jonathan Maple <[email protected]>
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…cesses Acquire a lock on kvm->srcu when userspace is getting MP state to handle a rather extreme edge case where "accepting" APIC events, i.e. processing pending INIT or SIPI, can trigger accesses to guest memory. If the vCPU is in L2 with INIT *and* a TRIPLE_FAULT request pending, then getting MP state will trigger a nested VM-Exit by way of ->check_nested_events(), and emuating the nested VM-Exit can access guest memory. The splat was originally hit by syzkaller on a Google-internal kernel, and reproduced on an upstream kernel by hacking the triple_fault_event_test selftest to stuff a pending INIT, store an MSR on VM-Exit (to generate a memory access on VMX), and do vcpu_mp_state_get() to trigger the scenario. ============================= WARNING: suspicious RCU usage 6.14.0-rc3-b112d356288b-vmx/pi_lockdep_false_pos-lock #3 Not tainted ----------------------------- include/linux/kvm_host.h:1058 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by triple_fault_ev/1256: #0: ffff88810df5a330 (&vcpu->mutex){+.+.}-{4:4}, at: kvm_vcpu_ioctl+0x8b/0x9a0 [kvm] stack backtrace: CPU: 11 UID: 1000 PID: 1256 Comm: triple_fault_ev Not tainted 6.14.0-rc3-b112d356288b-vmx #3 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: <TASK> dump_stack_lvl+0x7f/0x90 lockdep_rcu_suspicious+0x144/0x190 kvm_vcpu_gfn_to_memslot+0x156/0x180 [kvm] kvm_vcpu_read_guest+0x3e/0x90 [kvm] read_and_check_msr_entry+0x2e/0x180 [kvm_intel] __nested_vmx_vmexit+0x550/0xde0 [kvm_intel] kvm_check_nested_events+0x1b/0x30 [kvm] kvm_apic_accept_events+0x33/0x100 [kvm] kvm_arch_vcpu_ioctl_get_mpstate+0x30/0x1d0 [kvm] kvm_vcpu_ioctl+0x33e/0x9a0 [kvm] __x64_sys_ioctl+0x8b/0xb0 do_syscall_64+0x6c/0x170 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> Cc: [email protected] Signed-off-by: Sean Christopherson <[email protected]> Message-ID: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
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jira LE-2742 Rebuild_History Non-Buildable kernel-5.14.0-503.35.1.el9_5 commit-author Li Lingfeng <[email protected]> commit b313a8c Lockdep reported a warning in Linux version 6.6: [ 414.344659] ================================ [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.345155] WARNING: inconsistent lock state [ 414.345658] 6.6.0-07439-gba2303cacfda #6 Not tainted [ 414.346221] -------------------------------- [ 414.346712] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. [ 414.347545] kworker/u10:3/1152 [HC0[0]:SC0[0]:HE0:SE1] takes: [ 414.349245] ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.351204] {IN-SOFTIRQ-W} state was registered at: [ 414.351751] lock_acquire+0x18d/0x460 [ 414.352218] _raw_spin_lock_irqsave+0x39/0x60 [ 414.352769] __wake_up_common_lock+0x22/0x60 [ 414.353289] sbitmap_queue_wake_up+0x375/0x4f0 [ 414.353829] sbitmap_queue_clear+0xdd/0x270 [ 414.354338] blk_mq_put_tag+0xdf/0x170 [ 414.354807] __blk_mq_free_request+0x381/0x4d0 [ 414.355335] blk_mq_free_request+0x28b/0x3e0 [ 414.355847] __blk_mq_end_request+0x242/0xc30 [ 414.356367] scsi_end_request+0x2c1/0x830 [ 414.356863] scsi_io_completion+0x177/0x1610 [ 414.357379] scsi_complete+0x12f/0x260 [ 414.357856] blk_complete_reqs+0xba/0xf0 [ 414.358338] __do_softirq+0x1b0/0x7a2 [ 414.358796] irq_exit_rcu+0x14b/0x1a0 [ 414.359262] sysvec_call_function_single+0xaf/0xc0 [ 414.359828] asm_sysvec_call_function_single+0x1a/0x20 [ 414.360426] default_idle+0x1e/0x30 [ 414.360873] default_idle_call+0x9b/0x1f0 [ 414.361390] do_idle+0x2d2/0x3e0 [ 414.361819] cpu_startup_entry+0x55/0x60 [ 414.362314] start_secondary+0x235/0x2b0 [ 414.362809] secondary_startup_64_no_verify+0x18f/0x19b [ 414.363413] irq event stamp: 428794 [ 414.363825] hardirqs last enabled at (428793): [<ffffffff816bfd1c>] ktime_get+0x1dc/0x200 [ 414.364694] hardirqs last disabled at (428794): [<ffffffff85470177>] _raw_spin_lock_irq+0x47/0x50 [ 414.365629] softirqs last enabled at (428444): [<ffffffff85474780>] __do_softirq+0x540/0x7a2 [ 414.366522] softirqs last disabled at (428419): [<ffffffff813f65ab>] irq_exit_rcu+0x14b/0x1a0 [ 414.367425] other info that might help us debug this: [ 414.368194] Possible unsafe locking scenario: [ 414.368900] CPU0 [ 414.369225] ---- [ 414.369548] lock(&sbq->ws[i].wait); [ 414.370000] <Interrupt> [ 414.370342] lock(&sbq->ws[i].wait); [ 414.370802] *** DEADLOCK *** [ 414.371569] 5 locks held by kworker/u10:3/1152: [ 414.372088] #0: ffff88810130e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x357/0x13f0 [ 414.373180] #1: ffff88810201fdb8 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x3a3/0x13f0 [ 414.374384] #2: ffffffff86ffbdc0 (rcu_read_lock){....}-{1:2}, at: blk_mq_run_hw_queue+0x637/0xa00 [ 414.375342] #3: ffff88810edd1098 (&sbq->ws[i].wait){+.?.}-{2:2}, at: blk_mq_dispatch_rq_list+0x131c/0x1ee0 [ 414.376377] #4: ffff888106205a08 (&hctx->dispatch_wait_lock){+.-.}-{2:2}, at: blk_mq_dispatch_rq_list+0x1337/0x1ee0 [ 414.378607] stack backtrace: [ 414.379177] CPU: 0 PID: 1152 Comm: kworker/u10:3 Not tainted 6.6.0-07439-gba2303cacfda #6 [ 414.380032] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 414.381177] Workqueue: writeback wb_workfn (flush-253:0) [ 414.381805] Call Trace: [ 414.382136] <TASK> [ 414.382429] dump_stack_lvl+0x91/0xf0 [ 414.382884] mark_lock_irq+0xb3b/0x1260 [ 414.383367] ? __pfx_mark_lock_irq+0x10/0x10 [ 414.383889] ? stack_trace_save+0x8e/0xc0 [ 414.384373] ? __pfx_stack_trace_save+0x10/0x10 [ 414.384903] ? graph_lock+0xcf/0x410 [ 414.385350] ? save_trace+0x3d/0xc70 [ 414.385808] mark_lock.part.20+0x56d/0xa90 [ 414.386317] mark_held_locks+0xb0/0x110 [ 414.386791] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.387320] lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.387901] ? _raw_spin_unlock_irq+0x28/0x50 [ 414.388422] trace_hardirqs_on+0x58/0x100 [ 414.388917] _raw_spin_unlock_irq+0x28/0x50 [ 414.389422] __blk_mq_tag_busy+0x1d6/0x2a0 [ 414.389920] __blk_mq_get_driver_tag+0x761/0x9f0 [ 414.390899] blk_mq_dispatch_rq_list+0x1780/0x1ee0 [ 414.391473] ? __pfx_blk_mq_dispatch_rq_list+0x10/0x10 [ 414.392070] ? sbitmap_get+0x2b8/0x450 [ 414.392533] ? __blk_mq_get_driver_tag+0x210/0x9f0 [ 414.393095] __blk_mq_sched_dispatch_requests+0xd99/0x1690 [ 414.393730] ? elv_attempt_insert_merge+0x1b1/0x420 [ 414.394302] ? __pfx___blk_mq_sched_dispatch_requests+0x10/0x10 [ 414.394970] ? lock_acquire+0x18d/0x460 [ 414.395456] ? blk_mq_run_hw_queue+0x637/0xa00 [ 414.395986] ? __pfx_lock_acquire+0x10/0x10 [ 414.396499] blk_mq_sched_dispatch_requests+0x109/0x190 [ 414.397100] blk_mq_run_hw_queue+0x66e/0xa00 [ 414.397616] blk_mq_flush_plug_list.part.17+0x614/0x2030 [ 414.398244] ? __pfx_blk_mq_flush_plug_list.part.17+0x10/0x10 [ 414.398897] ? writeback_sb_inodes+0x241/0xcc0 [ 414.399429] blk_mq_flush_plug_list+0x65/0x80 [ 414.399957] __blk_flush_plug+0x2f1/0x530 [ 414.400458] ? __pfx___blk_flush_plug+0x10/0x10 [ 414.400999] blk_finish_plug+0x59/0xa0 [ 414.401467] wb_writeback+0x7cc/0x920 [ 414.401935] ? __pfx_wb_writeback+0x10/0x10 [ 414.402442] ? mark_held_locks+0xb0/0x110 [ 414.402931] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 414.403462] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.404062] wb_workfn+0x2b3/0xcf0 [ 414.404500] ? __pfx_wb_workfn+0x10/0x10 [ 414.404989] process_scheduled_works+0x432/0x13f0 [ 414.405546] ? __pfx_process_scheduled_works+0x10/0x10 [ 414.406139] ? do_raw_spin_lock+0x101/0x2a0 [ 414.406641] ? assign_work+0x19b/0x240 [ 414.407106] ? lock_is_held_type+0x9d/0x110 [ 414.407604] worker_thread+0x6f2/0x1160 [ 414.408075] ? __kthread_parkme+0x62/0x210 [ 414.408572] ? lockdep_hardirqs_on_prepare+0x297/0x3f0 [ 414.409168] ? __kthread_parkme+0x13c/0x210 [ 414.409678] ? __pfx_worker_thread+0x10/0x10 [ 414.410191] kthread+0x33c/0x440 [ 414.410602] ? __pfx_kthread+0x10/0x10 [ 414.411068] ret_from_fork+0x4d/0x80 [ 414.411526] ? __pfx_kthread+0x10/0x10 [ 414.411993] ret_from_fork_asm+0x1b/0x30 [ 414.412489] </TASK> When interrupt is turned on while a lock holding by spin_lock_irq it throws a warning because of potential deadlock. blk_mq_prep_dispatch_rq blk_mq_get_driver_tag __blk_mq_get_driver_tag __blk_mq_alloc_driver_tag blk_mq_tag_busy -> tag is already busy // failed to get driver tag blk_mq_mark_tag_wait spin_lock_irq(&wq->lock) -> lock A (&sbq->ws[i].wait) __add_wait_queue(wq, wait) -> wait queue active blk_mq_get_driver_tag __blk_mq_tag_busy -> 1) tag must be idle, which means there can't be inflight IO spin_lock_irq(&tags->lock) -> lock B (hctx->tags) spin_unlock_irq(&tags->lock) -> unlock B, turn on interrupt accidentally -> 2) context must be preempt by IO interrupt to trigger deadlock. As shown above, the deadlock is not possible in theory, but the warning still need to be fixed. Fix it by using spin_lock_irqsave to get lockB instead of spin_lock_irq. Fixes: 4f1731d ("blk-mq: fix potential io hang by wrong 'wake_batch'") Signed-off-by: Li Lingfeng <[email protected]> Reviewed-by: Ming Lei <[email protected]> Reviewed-by: Yu Kuai <[email protected]> Reviewed-by: Bart Van Assche <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> (cherry picked from commit b313a8c) Signed-off-by: Jonathan Maple <[email protected]>
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…ate_pagetables' [ Upstream commit fddc450 ] This commit addresses a circular locking dependency in the svm_range_cpu_invalidate_pagetables function. The function previously held a lock while determining whether to perform an unmap or eviction operation, which could lead to deadlocks. Fixes the below: [ 223.418794] ====================================================== [ 223.418820] WARNING: possible circular locking dependency detected [ 223.418845] 6.12.0-amdstaging-drm-next-lol-050225 #14 Tainted: G U OE [ 223.418869] ------------------------------------------------------ [ 223.418889] kfdtest/3939 is trying to acquire lock: [ 223.418906] ffff8957552eae38 (&dqm->lock_hidden){+.+.}-{3:3}, at: evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.419302] but task is already holding lock: [ 223.419303] ffff8957556b83b0 (&prange->lock){+.+.}-{3:3}, at: svm_range_cpu_invalidate_pagetables+0x9d/0x850 [amdgpu] [ 223.419447] Console: switching to colour dummy device 80x25 [ 223.419477] [IGT] amd_basic: executing [ 223.419599] which lock already depends on the new lock. [ 223.419611] the existing dependency chain (in reverse order) is: [ 223.419621] -> #2 (&prange->lock){+.+.}-{3:3}: [ 223.419636] __mutex_lock+0x85/0xe20 [ 223.419647] mutex_lock_nested+0x1b/0x30 [ 223.419656] svm_range_validate_and_map+0x2f1/0x15b0 [amdgpu] [ 223.419954] svm_range_set_attr+0xe8c/0x1710 [amdgpu] [ 223.420236] svm_ioctl+0x46/0x50 [amdgpu] [ 223.420503] kfd_ioctl_svm+0x50/0x90 [amdgpu] [ 223.420763] kfd_ioctl+0x409/0x6d0 [amdgpu] [ 223.421024] __x64_sys_ioctl+0x95/0xd0 [ 223.421036] x64_sys_call+0x1205/0x20d0 [ 223.421047] do_syscall_64+0x87/0x140 [ 223.421056] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 223.421068] -> #1 (reservation_ww_class_mutex){+.+.}-{3:3}: [ 223.421084] __ww_mutex_lock.constprop.0+0xab/0x1560 [ 223.421095] ww_mutex_lock+0x2b/0x90 [ 223.421103] amdgpu_amdkfd_alloc_gtt_mem+0xcc/0x2b0 [amdgpu] [ 223.421361] add_queue_mes+0x3bc/0x440 [amdgpu] [ 223.421623] unhalt_cpsch+0x1ae/0x240 [amdgpu] [ 223.421888] kgd2kfd_start_sched+0x5e/0xd0 [amdgpu] [ 223.422148] amdgpu_amdkfd_start_sched+0x3d/0x50 [amdgpu] [ 223.422414] amdgpu_gfx_enforce_isolation_handler+0x132/0x270 [amdgpu] [ 223.422662] process_one_work+0x21e/0x680 [ 223.422673] worker_thread+0x190/0x330 [ 223.422682] kthread+0xe7/0x120 [ 223.422690] ret_from_fork+0x3c/0x60 [ 223.422699] ret_from_fork_asm+0x1a/0x30 [ 223.422708] -> #0 (&dqm->lock_hidden){+.+.}-{3:3}: [ 223.422723] __lock_acquire+0x16f4/0x2810 [ 223.422734] lock_acquire+0xd1/0x300 [ 223.422742] __mutex_lock+0x85/0xe20 [ 223.422751] mutex_lock_nested+0x1b/0x30 [ 223.422760] evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.423025] kfd_process_evict_queues+0x8a/0x1d0 [amdgpu] [ 223.423285] kgd2kfd_quiesce_mm+0x43/0x90 [amdgpu] [ 223.423540] svm_range_cpu_invalidate_pagetables+0x4a7/0x850 [amdgpu] [ 223.423807] __mmu_notifier_invalidate_range_start+0x1f5/0x250 [ 223.423819] copy_page_range+0x1e94/0x1ea0 [ 223.423829] copy_process+0x172f/0x2ad0 [ 223.423839] kernel_clone+0x9c/0x3f0 [ 223.423847] __do_sys_clone+0x66/0x90 [ 223.423856] __x64_sys_clone+0x25/0x30 [ 223.423864] x64_sys_call+0x1d7c/0x20d0 [ 223.423872] do_syscall_64+0x87/0x140 [ 223.423880] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 223.423891] other info that might help us debug this: [ 223.423903] Chain exists of: &dqm->lock_hidden --> reservation_ww_class_mutex --> &prange->lock [ 223.423926] Possible unsafe locking scenario: [ 223.423935] CPU0 CPU1 [ 223.423942] ---- ---- [ 223.423949] lock(&prange->lock); [ 223.423958] lock(reservation_ww_class_mutex); [ 223.423970] lock(&prange->lock); [ 223.423981] lock(&dqm->lock_hidden); [ 223.423990] *** DEADLOCK *** [ 223.423999] 5 locks held by kfdtest/3939: [ 223.424006] #0: ffffffffb82b4fc0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_process+0x1387/0x2ad0 [ 223.424026] #1: ffff89575eda81b0 (&mm->mmap_lock){++++}-{3:3}, at: copy_process+0x13a8/0x2ad0 [ 223.424046] #2: ffff89575edaf3b0 (&mm->mmap_lock/1){+.+.}-{3:3}, at: copy_process+0x13e4/0x2ad0 [ 223.424066] #3: ffffffffb82e76e0 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}, at: copy_page_range+0x1cea/0x1ea0 [ 223.424088] #4: ffff8957556b83b0 (&prange->lock){+.+.}-{3:3}, at: svm_range_cpu_invalidate_pagetables+0x9d/0x850 [amdgpu] [ 223.424365] stack backtrace: [ 223.424374] CPU: 0 UID: 0 PID: 3939 Comm: kfdtest Tainted: G U OE 6.12.0-amdstaging-drm-next-lol-050225 #14 [ 223.424392] Tainted: [U]=USER, [O]=OOT_MODULE, [E]=UNSIGNED_MODULE [ 223.424401] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS PRO WIFI/X570 AORUS PRO WIFI, BIOS F36a 02/16/2022 [ 223.424416] Call Trace: [ 223.424423] <TASK> [ 223.424430] dump_stack_lvl+0x9b/0xf0 [ 223.424441] dump_stack+0x10/0x20 [ 223.424449] print_circular_bug+0x275/0x350 [ 223.424460] check_noncircular+0x157/0x170 [ 223.424469] ? __bfs+0xfd/0x2c0 [ 223.424481] __lock_acquire+0x16f4/0x2810 [ 223.424490] ? srso_return_thunk+0x5/0x5f [ 223.424505] lock_acquire+0xd1/0x300 [ 223.424514] ? evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.424783] __mutex_lock+0x85/0xe20 [ 223.424792] ? evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.425058] ? srso_return_thunk+0x5/0x5f [ 223.425067] ? mark_held_locks+0x54/0x90 [ 223.425076] ? evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.425339] ? srso_return_thunk+0x5/0x5f [ 223.425350] mutex_lock_nested+0x1b/0x30 [ 223.425358] ? mutex_lock_nested+0x1b/0x30 [ 223.425367] evict_process_queues_cpsch+0x43/0x210 [amdgpu] [ 223.425631] kfd_process_evict_queues+0x8a/0x1d0 [amdgpu] [ 223.425893] kgd2kfd_quiesce_mm+0x43/0x90 [amdgpu] [ 223.426156] svm_range_cpu_invalidate_pagetables+0x4a7/0x850 [amdgpu] [ 223.426423] ? srso_return_thunk+0x5/0x5f [ 223.426436] __mmu_notifier_invalidate_range_start+0x1f5/0x250 [ 223.426450] copy_page_range+0x1e94/0x1ea0 [ 223.426461] ? srso_return_thunk+0x5/0x5f [ 223.426474] ? srso_return_thunk+0x5/0x5f [ 223.426484] ? lock_acquire+0xd1/0x300 [ 223.426494] ? copy_process+0x1718/0x2ad0 [ 223.426502] ? srso_return_thunk+0x5/0x5f [ 223.426510] ? sched_clock_noinstr+0x9/0x10 [ 223.426519] ? local_clock_noinstr+0xe/0xc0 [ 223.426528] ? copy_process+0x1718/0x2ad0 [ 223.426537] ? srso_return_thunk+0x5/0x5f [ 223.426550] copy_process+0x172f/0x2ad0 [ 223.426569] kernel_clone+0x9c/0x3f0 [ 223.426577] ? __schedule+0x4c9/0x1b00 [ 223.426586] ? srso_return_thunk+0x5/0x5f [ 223.426594] ? sched_clock_noinstr+0x9/0x10 [ 223.426602] ? srso_return_thunk+0x5/0x5f [ 223.426610] ? local_clock_noinstr+0xe/0xc0 [ 223.426619] ? schedule+0x107/0x1a0 [ 223.426629] __do_sys_clone+0x66/0x90 [ 223.426643] __x64_sys_clone+0x25/0x30 [ 223.426652] x64_sys_call+0x1d7c/0x20d0 [ 223.426661] do_syscall_64+0x87/0x140 [ 223.426671] ? srso_return_thunk+0x5/0x5f [ 223.426679] ? common_nsleep+0x44/0x50 [ 223.426690] ? srso_return_thunk+0x5/0x5f [ 223.426698] ? trace_hardirqs_off+0x52/0xd0 [ 223.426709] ? srso_return_thunk+0x5/0x5f [ 223.426717] ? syscall_exit_to_user_mode+0xcc/0x200 [ 223.426727] ? srso_return_thunk+0x5/0x5f [ 223.426736] ? do_syscall_64+0x93/0x140 [ 223.426748] ? srso_return_thunk+0x5/0x5f [ 223.426756] ? up_write+0x1c/0x1e0 [ 223.426765] ? srso_return_thunk+0x5/0x5f [ 223.426775] ? srso_return_thunk+0x5/0x5f [ 223.426783] ? trace_hardirqs_off+0x52/0xd0 [ 223.426792] ? srso_return_thunk+0x5/0x5f [ 223.426800] ? syscall_exit_to_user_mode+0xcc/0x200 [ 223.426810] ? srso_return_thunk+0x5/0x5f [ 223.426818] ? do_syscall_64+0x93/0x140 [ 223.426826] ? syscall_exit_to_user_mode+0xcc/0x200 [ 223.426836] ? srso_return_thunk+0x5/0x5f [ 223.426844] ? do_syscall_64+0x93/0x140 [ 223.426853] ? srso_return_thunk+0x5/0x5f [ 223.426861] ? irqentry_exit+0x6b/0x90 [ 223.426869] ? srso_return_thunk+0x5/0x5f [ 223.426877] ? exc_page_fault+0xa7/0x2c0 [ 223.426888] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 223.426898] RIP: 0033:0x7f46758eab57 [ 223.426906] Code: ba 04 00 f3 0f 1e fa 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 41 89 c0 85 c0 75 2c 64 48 8b 04 25 10 00 [ 223.426930] RSP: 002b:00007fff5c3e5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 [ 223.426943] RAX: ffffffffffffffda RBX: 00007f4675f8c040 RCX: 00007f46758eab57 [ 223.426954] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 [ 223.426965] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 223.426975] R10: 00007f4675e81a50 R11: 0000000000000246 R12: 0000000000000001 [ 223.426986] R13: 00007fff5c3e5470 R14: 00007fff5c3e53e0 R15: 00007fff5c3e5410 [ 223.427004] </TASK> v2: To resolve this issue, the allocation of the process context buffer (`proc_ctx_bo`) has been moved from the `add_queue_mes` function to the `pqm_create_queue` function. This change ensures that the buffer is allocated only when the first queue for a process is created and only if the Micro Engine Scheduler (MES) is enabled. (Felix) v3: Fix typo s/Memory Execution Scheduler (MES)/Micro Engine Scheduler in commit message. (Lijo) Fixes: 438b39a ("drm/amdkfd: pause autosuspend when creating pdd") Cc: Jesse Zhang <[email protected]> Cc: Yunxiang Li <[email protected]> Cc: Philip Yang <[email protected]> Cc: Alex Sierra <[email protected]> Cc: Felix Kuehling <[email protected]> Cc: Christian König <[email protected]> Cc: Alex Deucher <[email protected]> Signed-off-by: Srinivasan Shanmugam <[email protected]> Reviewed-by: Felix Kuehling <[email protected]> Signed-off-by: Alex Deucher <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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…cal section [ Upstream commit 85b2b9c ] A circular lock dependency splat has been seen involving down_trylock(): ====================================================== WARNING: possible circular locking dependency detected 6.12.0-41.el10.s390x+debug ------------------------------------------------------ dd/32479 is trying to acquire lock: 0015a20accd0d4f8 ((console_sem).lock){-.-.}-{2:2}, at: down_trylock+0x26/0x90 but task is already holding lock: 000000017e461698 (&zone->lock){-.-.}-{2:2}, at: rmqueue_bulk+0xac/0x8f0 the existing dependency chain (in reverse order) is: -> #4 (&zone->lock){-.-.}-{2:2}: -> #3 (hrtimer_bases.lock){-.-.}-{2:2}: -> #2 (&rq->__lock){-.-.}-{2:2}: -> #1 (&p->pi_lock){-.-.}-{2:2}: -> #0 ((console_sem).lock){-.-.}-{2:2}: The console_sem -> pi_lock dependency is due to calling try_to_wake_up() while holding the console_sem raw_spinlock. This dependency can be broken by using wake_q to do the wakeup instead of calling try_to_wake_up() under the console_sem lock. This will also make the semaphore's raw_spinlock become a terminal lock without taking any further locks underneath it. The hrtimer_bases.lock is a raw_spinlock while zone->lock is a spinlock. The hrtimer_bases.lock -> zone->lock dependency happens via the debug_objects_fill_pool() helper function in the debugobjects code. -> #4 (&zone->lock){-.-.}-{2:2}: __lock_acquire+0xe86/0x1cc0 lock_acquire.part.0+0x258/0x630 lock_acquire+0xb8/0xe0 _raw_spin_lock_irqsave+0xb4/0x120 rmqueue_bulk+0xac/0x8f0 __rmqueue_pcplist+0x580/0x830 rmqueue_pcplist+0xfc/0x470 rmqueue.isra.0+0xdec/0x11b0 get_page_from_freelist+0x2ee/0xeb0 __alloc_pages_noprof+0x2c2/0x520 alloc_pages_mpol_noprof+0x1fc/0x4d0 alloc_pages_noprof+0x8c/0xe0 allocate_slab+0x320/0x460 ___slab_alloc+0xa58/0x12b0 __slab_alloc.isra.0+0x42/0x60 kmem_cache_alloc_noprof+0x304/0x350 fill_pool+0xf6/0x450 debug_object_activate+0xfe/0x360 enqueue_hrtimer+0x34/0x190 __run_hrtimer+0x3c8/0x4c0 __hrtimer_run_queues+0x1b2/0x260 hrtimer_interrupt+0x316/0x760 do_IRQ+0x9a/0xe0 do_irq_async+0xf6/0x160 Normally a raw_spinlock to spinlock dependency is not legitimate and will be warned if CONFIG_PROVE_RAW_LOCK_NESTING is enabled, but debug_objects_fill_pool() is an exception as it explicitly allows this dependency for non-PREEMPT_RT kernel without causing PROVE_RAW_LOCK_NESTING lockdep splat. As a result, this dependency is legitimate and not a bug. Anyway, semaphore is the only locking primitive left that is still using try_to_wake_up() to do wakeup inside critical section, all the other locking primitives had been migrated to use wake_q to do wakeup outside of the critical section. It is also possible that there are other circular locking dependencies involving printk/console_sem or other existing/new semaphores lurking somewhere which may show up in the future. Let just do the migration now to wake_q to avoid headache like this. Reported-by: [email protected] Signed-off-by: Waiman Long <[email protected]> Signed-off-by: Boqun Feng <[email protected]> Signed-off-by: Ingo Molnar <[email protected]> Cc: Linus Torvalds <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 053f3ff ] v2: - Created a single error handling unlock and exit in veth_pool_store - Greatly expanded commit message with previous explanatory-only text Summary: Use rtnl_mutex to synchronize veth_pool_store with itself, ibmveth_close and ibmveth_open, preventing multiple calls in a row to napi_disable. Background: Two (or more) threads could call veth_pool_store through writing to /sys/devices/vio/30000002/pool*/*. You can do this easily with a little shell script. This causes a hang. I configured LOCKDEP, compiled ibmveth.c with DEBUG, and built a new kernel. I ran this test again and saw: Setting pool0/active to 0 Setting pool1/active to 1 [ 73.911067][ T4365] ibmveth 30000002 eth0: close starting Setting pool1/active to 1 Setting pool1/active to 0 [ 73.911367][ T4366] ibmveth 30000002 eth0: close starting [ 73.916056][ T4365] ibmveth 30000002 eth0: close complete [ 73.916064][ T4365] ibmveth 30000002 eth0: open starting [ 110.808564][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification. [ 230.808495][ T712] systemd-journald[712]: Sent WATCHDOG=1 notification. [ 243.683786][ T123] INFO: task stress.sh:4365 blocked for more than 122 seconds. [ 243.683827][ T123] Not tainted 6.14.0-01103-g2df0c02dab82-dirty #8 [ 243.683833][ T123] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 243.683838][ T123] task:stress.sh state:D stack:28096 pid:4365 tgid:4365 ppid:4364 task_flags:0x400040 flags:0x00042000 [ 243.683852][ T123] Call Trace: [ 243.683857][ T123] [c00000000c38f690] [0000000000000001] 0x1 (unreliable) [ 243.683868][ T123] [c00000000c38f840] [c00000000001f908] __switch_to+0x318/0x4e0 [ 243.683878][ T123] [c00000000c38f8a0] [c000000001549a70] __schedule+0x500/0x12a0 [ 243.683888][ T123] [c00000000c38f9a0] [c00000000154a878] schedule+0x68/0x210 [ 243.683896][ T123] [c00000000c38f9d0] [c00000000154ac80] schedule_preempt_disabled+0x30/0x50 [ 243.683904][ T123] [c00000000c38fa00] [c00000000154dbb0] __mutex_lock+0x730/0x10f0 [ 243.683913][ T123] [c00000000c38fb10] [c000000001154d40] napi_enable+0x30/0x60 [ 243.683921][ T123] [c00000000c38fb40] [c000000000f4ae94] ibmveth_open+0x68/0x5dc [ 243.683928][ T123] [c00000000c38fbe0] [c000000000f4aa20] veth_pool_store+0x220/0x270 [ 243.683936][ T123] [c00000000c38fc70] [c000000000826278] sysfs_kf_write+0x68/0xb0 [ 243.683944][ T123] [c00000000c38fcb0] [c0000000008240b8] kernfs_fop_write_iter+0x198/0x2d0 [ 243.683951][ T123] [c00000000c38fd00] [c00000000071b9ac] vfs_write+0x34c/0x650 [ 243.683958][ T123] [c00000000c38fdc0] [c00000000071bea8] ksys_write+0x88/0x150 [ 243.683966][ T123] [c00000000c38fe10] [c0000000000317f4] system_call_exception+0x124/0x340 [ 243.683973][ T123] [c00000000c38fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec ... [ 243.684087][ T123] Showing all locks held in the system: [ 243.684095][ T123] 1 lock held by khungtaskd/123: [ 243.684099][ T123] #0: c00000000278e370 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x50/0x248 [ 243.684114][ T123] 4 locks held by stress.sh/4365: [ 243.684119][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150 [ 243.684132][ T123] #1: c000000041aea888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0 [ 243.684143][ T123] #2: c0000000366fb9a8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0 [ 243.684155][ T123] #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_enable+0x30/0x60 [ 243.684166][ T123] 5 locks held by stress.sh/4366: [ 243.684170][ T123] #0: c00000003a4cd3f8 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x88/0x150 [ 243.684183][ T123] #1: c00000000aee2288 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x154/0x2d0 [ 243.684194][ T123] #2: c0000000366f4ba8 (kn->active#64){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x160/0x2d0 [ 243.684205][ T123] #3: c000000035ff4cb8 (&dev->lock){+.+.}-{3:3}, at: napi_disable+0x30/0x60 [ 243.684216][ T123] #4: c0000003ff9bbf18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x138/0x12a0 From the ibmveth debug, two threads are calling veth_pool_store, which calls ibmveth_close and ibmveth_open. Here's the sequence: T4365 T4366 ----------------- ----------------- --------- veth_pool_store veth_pool_store ibmveth_close ibmveth_close napi_disable napi_disable ibmveth_open napi_enable <- HANG ibmveth_close calls napi_disable at the top and ibmveth_open calls napi_enable at the top. https://docs.kernel.org/networking/napi.html]] says The control APIs are not idempotent. Control API calls are safe against concurrent use of datapath APIs but an incorrect sequence of control API calls may result in crashes, deadlocks, or race conditions. For example, calling napi_disable() multiple times in a row will deadlock. In the normal open and close paths, rtnl_mutex is acquired to prevent other callers. This is missing from veth_pool_store. Use rtnl_mutex in veth_pool_store fixes these hangs. Signed-off-by: Dave Marquardt <[email protected]> Fixes: 860f242 ("[PATCH] ibmveth change buffer pools dynamically") Reviewed-by: Nick Child <[email protected]> Reviewed-by: Simon Horman <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 52323ed ] syzbot reported a deadlock in lock_system_sleep() (see below). The write operation to "/sys/module/hibernate/parameters/compressor" conflicts with the registration of ieee80211 device, resulting in a deadlock when attempting to acquire system_transition_mutex under param_lock. To avoid this deadlock, change hibernate_compressor_param_set() to use mutex_trylock() for attempting to acquire system_transition_mutex and return -EBUSY when it fails. Task flags need not be saved or adjusted before calling mutex_trylock(&system_transition_mutex) because the caller is not going to end up waiting for this mutex and if it runs concurrently with system suspend in progress, it will be frozen properly when it returns to user space. syzbot report: syz-executor895/5833 is trying to acquire lock: ffffffff8e0828c8 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 but task is already holding lock: ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: kernel_param_lock kernel/params.c:607 [inline] ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: param_attr_store+0xe6/0x300 kernel/params.c:586 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (param_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 ieee80211_rate_control_ops_get net/mac80211/rate.c:220 [inline] rate_control_alloc net/mac80211/rate.c:266 [inline] ieee80211_init_rate_ctrl_alg+0x18d/0x6b0 net/mac80211/rate.c:1015 ieee80211_register_hw+0x20cd/0x4060 net/mac80211/main.c:1531 mac80211_hwsim_new_radio+0x304e/0x54e0 drivers/net/wireless/virtual/mac80211_hwsim.c:5558 init_mac80211_hwsim+0x432/0x8c0 drivers/net/wireless/virtual/mac80211_hwsim.c:6910 do_one_initcall+0x128/0x700 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1568 kernel_init+0x1c/0x2b0 init/main.c:1457 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #2 (rtnl_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 wg_pm_notification drivers/net/wireguard/device.c:80 [inline] wg_pm_notification+0x49/0x180 drivers/net/wireguard/device.c:64 notifier_call_chain+0xb7/0x410 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline] blocking_notifier_call_chain_robust+0xc9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 ((pm_chain_head).rwsem){++++}-{4:4}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1524 blocking_notifier_call_chain_robust kernel/notifier.c:344 [inline] blocking_notifier_call_chain_robust+0xa9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (system_transition_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 hibernate_compressor_param_set+0x1c/0x210 kernel/power/hibernate.c:1452 param_attr_store+0x18f/0x300 kernel/params.c:588 module_attr_store+0x55/0x80 kernel/params.c:924 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x33d/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: system_transition_mutex --> rtnl_mutex --> param_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(param_lock); lock(rtnl_mutex); lock(param_lock); lock(system_transition_mutex); *** DEADLOCK *** Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=ace60642828c074eb913 Signed-off-by: Lizhi Xu <[email protected]> Link: https://patch.msgid.link/[email protected] [ rjw: New subject matching the code changes, changelog edits ] Signed-off-by: Rafael J. Wysocki <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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Apr 20, 2025
[ Upstream commit b61e69b ] syzbot report a deadlock in diFree. [1] When calling "ioctl$LOOP_SET_STATUS64", the offset value passed in is 4, which does not match the mounted loop device, causing the mapping of the mounted loop device to be invalidated. When creating the directory and creating the inode of iag in diReadSpecial(), read the page of fixed disk inode (AIT) in raw mode in read_metapage(), the metapage data it returns is corrupted, which causes the nlink value of 0 to be assigned to the iag inode when executing copy_from_dinode(), which ultimately causes a deadlock when entering diFree(). To avoid this, first check the nlink value of dinode before setting iag inode. [1] WARNING: possible recursive locking detected 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Not tainted -------------------------------------------- syz-executor301/5309 is trying to acquire lock: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889 but task is already holding lock: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(imap->im_aglock[index])); lock(&(imap->im_aglock[index])); *** DEADLOCK *** May be due to missing lock nesting notation 5 locks held by syz-executor301/5309: #0: ffff8880422a4420 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:515 #1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:850 [inline] #1: ffff88804755b390 (&type->i_mutex_dir_key#6/1){+.+.}-{3:3}, at: filename_create+0x260/0x540 fs/namei.c:4026 #2: ffff888044548920 (&(imap->im_aglock[index])){+.+.}-{3:3}, at: diAlloc+0x1b6/0x1630 #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2460 [inline] #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline] #3: ffff888044548890 (&imap->im_freelock){+.+.}-{3:3}, at: diAllocAG+0x4b7/0x1e50 fs/jfs/jfs_imap.c:1669 #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diNewIAG fs/jfs/jfs_imap.c:2477 [inline] #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocExt fs/jfs/jfs_imap.c:1905 [inline] #4: ffff88804755a618 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: diAllocAG+0x869/0x1e50 fs/jfs/jfs_imap.c:1669 stack backtrace: CPU: 0 UID: 0 PID: 5309 Comm: syz-executor301 Not tainted 6.12.0-rc7-syzkaller-00212-g4a5df3796467 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037 check_deadlock kernel/locking/lockdep.c:3089 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 diFree+0x37c/0x2fb0 fs/jfs/jfs_imap.c:889 jfs_evict_inode+0x32d/0x440 fs/jfs/inode.c:156 evict+0x4e8/0x9b0 fs/inode.c:725 diFreeSpecial fs/jfs/jfs_imap.c:552 [inline] duplicateIXtree+0x3c6/0x550 fs/jfs/jfs_imap.c:3022 diNewIAG fs/jfs/jfs_imap.c:2597 [inline] diAllocExt fs/jfs/jfs_imap.c:1905 [inline] diAllocAG+0x17dc/0x1e50 fs/jfs/jfs_imap.c:1669 diAlloc+0x1d2/0x1630 fs/jfs/jfs_imap.c:1590 ialloc+0x8f/0x900 fs/jfs/jfs_inode.c:56 jfs_mkdir+0x1c5/0xba0 fs/jfs/namei.c:225 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257 do_mkdirat+0x264/0x3a0 fs/namei.c:4280 __do_sys_mkdirat fs/namei.c:4295 [inline] __se_sys_mkdirat fs/namei.c:4293 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=355da3b3a74881008e8f Signed-off-by: Edward Adam Davis <[email protected]> Signed-off-by: Dave Kleikamp <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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This fixes the following UAF caused by not properly locking hdev when processing HCI_EV_NUM_COMP_PKTS: BUG: KASAN: slab-use-after-free in hci_conn_tx_dequeue+0x1be/0x220 net/bluetooth/hci_conn.c:3036 Read of size 4 at addr ffff8880740f0940 by task kworker/u11:0/54 CPU: 1 UID: 0 PID: 54 Comm: kworker/u11:0 Not tainted 6.16.0-rc7 #3 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Workqueue: hci1 hci_rx_work Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x230 mm/kasan/report.c:480 kasan_report+0x118/0x150 mm/kasan/report.c:593 hci_conn_tx_dequeue+0x1be/0x220 net/bluetooth/hci_conn.c:3036 hci_num_comp_pkts_evt+0x1c8/0xa50 net/bluetooth/hci_event.c:4404 hci_event_func net/bluetooth/hci_event.c:7477 [inline] hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 54: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] __hci_conn_add+0x233/0x1b30 net/bluetooth/hci_conn.c:939 le_conn_complete_evt+0x3d6/0x1220 net/bluetooth/hci_event.c:5628 hci_le_enh_conn_complete_evt+0x189/0x470 net/bluetooth/hci_event.c:5794 hci_event_func net/bluetooth/hci_event.c:7474 [inline] hci_event_packet+0x78c/0x1200 net/bluetooth/hci_event.c:7531 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 Freed by task 9572: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 device_release+0x9c/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline] hci_conn_del+0x8ff/0xcb0 net/bluetooth/hci_conn.c:1173 hci_abort_conn_sync+0x5d1/0xdf0 net/bluetooth/hci_sync.c:5689 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 Fixes: 134f4b3 ("Bluetooth: add support for skb TX SND/COMPLETION timestamping") Reported-by: Junvyyang, Tencent Zhuque Lab <[email protected]> Signed-off-by: Luiz Augusto von Dentz <[email protected]>
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This fixes the following UFA in hci_acl_create_conn_sync where a connection still pending is command submission (conn->state == BT_OPEN) maybe freed, also since this also can happen with the likes of hci_le_create_conn_sync fix it as well: BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0x5ef/0x790 net/bluetooth/hci_sync.c:6861 Write of size 2 at addr ffff88805ffcc038 by task kworker/u11:2/9541 CPU: 1 UID: 0 PID: 9541 Comm: kworker/u11:2 Not tainted 6.16.0-rc7 #3 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Workqueue: hci3 hci_cmd_sync_work Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x230 mm/kasan/report.c:480 kasan_report+0x118/0x150 mm/kasan/report.c:593 hci_acl_create_conn_sync+0x5ef/0x790 net/bluetooth/hci_sync.c:6861 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 123736: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] __hci_conn_add+0x233/0x1b30 net/bluetooth/hci_conn.c:939 hci_conn_add_unset net/bluetooth/hci_conn.c:1051 [inline] hci_connect_acl+0x16c/0x4e0 net/bluetooth/hci_conn.c:1634 pair_device+0x418/0xa70 net/bluetooth/mgmt.c:3556 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 sock_write_iter+0x258/0x330 net/socket.c:1131 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x54b/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 103680: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 device_release+0x9c/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline] hci_conn_del+0x8ff/0xcb0 net/bluetooth/hci_conn.c:1173 hci_conn_complete_evt+0x3c7/0x1040 net/bluetooth/hci_event.c:3199 hci_event_func net/bluetooth/hci_event.c:7477 [inline] hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 insert_work+0x3d/0x330 kernel/workqueue.c:2183 __queue_work+0xbd9/0xfe0 kernel/workqueue.c:2345 queue_delayed_work_on+0x18b/0x280 kernel/workqueue.c:2561 pairing_complete+0x1e7/0x2b0 net/bluetooth/mgmt.c:3451 pairing_complete_cb+0x1ac/0x230 net/bluetooth/mgmt.c:3487 hci_connect_cfm include/net/bluetooth/hci_core.h:2064 [inline] hci_conn_failed+0x24d/0x310 net/bluetooth/hci_conn.c:1275 hci_conn_complete_evt+0x3c7/0x1040 net/bluetooth/hci_event.c:3199 hci_event_func net/bluetooth/hci_event.c:7477 [inline] hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 Fixes: aef2aa4 ("Bluetooth: hci_event: Fix creating hci_conn object on error status") Reported-by: Junvyyang, Tencent Zhuque Lab <[email protected]> Signed-off-by: Luiz Augusto von Dentz <[email protected]>
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Ido Schimmel says: ==================== nexthop: Various fixes Patch #1 fixes a NPD that was recently reported by syzbot. Patch #2 fixes an issue in the existing FIB nexthop selftest. Patch #3 extends the selftest with test cases for the bug that was fixed in the first patch. ==================== Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
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JIRA: https://issues.redhat.com/browse/RHEL-107304 Upstream status: Linus CVE: CVE-2025-38498 Conflicts: There is a fuzz 1 for hunk #1 in fs/namespace.c. This is due to the lack of upstream commit 86b1da9 ("attach_recursive_mnt(): get rid of flags entirely"), and some earlier changes, which depends on a number of other patches that add function getname_maybe_null() among other changes. But the patches do to resolve the CVE and are well defined and without dependencies. Note that hunk #3 has been dropped from the upstream patch becuase it patched function do_set_group() which belongs to functionality (also described in the description of the upstream patch) not present in RHEL-9 and deemed no relevant to the CVE we are resolving. commit cffd044 Author: Al Viro <[email protected]> Date: Thu Aug 14 01:44:31 2025 -0400 use uniform permission checks for all mount propagation changes do_change_type() and do_set_group() are operating on different aspects of the same thing - propagation graph. The latter asks for mounts involved to be mounted in namespace(s) the caller has CAP_SYS_ADMIN for. The former is a mess - originally it didn't even check that mount *is* mounted. That got fixed, but the resulting check turns out to be too strict for userland - in effect, we check that mount is in our namespace, having already checked that we have CAP_SYS_ADMIN there. What we really need (in both cases) is * only touch mounts that are mounted. That's a must-have constraint - data corruption happens if it get violated. * don't allow to mess with a namespace unless you already have enough permissions to do so (i.e. CAP_SYS_ADMIN in its userns). That's an equivalent of what do_set_group() does; let's extract that into a helper (may_change_propagation()) and use it in both do_set_group() and do_change_type(). Fixes: 12f147d "do_change_type(): refuse to operate on unmounted/not ours mounts" Acked-by: Andrei Vagin <[email protected]> Reviewed-by: Pavel Tikhomirov <[email protected]> Tested-by: Pavel Tikhomirov <[email protected]> Reviewed-by: Christian Brauner <[email protected]> Signed-off-by: Al Viro <[email protected]> Signed-off-by: Ian Kent <[email protected]>
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We check the version of SPE twice, and we'll add one more check in the next commit so factor out a macro to do this. Change the #3 magic number to the actual SPE version define (V1p2) to make it more readable. No functional changes intended. Tested-by: Leo Yan <[email protected]> Reviewed-by: Leo Yan <[email protected]> Signed-off-by: James Clark <[email protected]> Signed-off-by: Will Deacon <[email protected]>
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JIRA: https://issues.redhat.com/browse/RHEL-101598 commit dc4824f Author: Mark Rutland <[email protected]> Date: Fri Jan 27 11:08:20 2023 +0000 arm64: avoid executing padding bytes during kexec / hibernation Currently we rely on the HIBERNATE_TEXT section starting with the entry point to swsusp_arch_suspend_exit, and the KEXEC_TEXT section starting with the entry point to arm64_relocate_new_kernel. In both cases we copy the entire section into a dynamically-allocated page, and then later branch to the start of this page. SYM_FUNC_START() will align the function entry points to CONFIG_FUNCTION_ALIGNMENT, and when the linker later processes the assembled code it will place padding bytes before the function entry point if the location counter was not already sufficiently aligned. The linker happens to use the value zero for these padding bytes. This padding may end up being applied whenever CONFIG_FUNCTION_ALIGNMENT is greater than 4, which can be the case with CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B=y or CONFIG_DYNAMIC_FTRACE_WITH_CALL_OPS=y. When such padding is applied, attempting to kexec or resume from hibernate will result ina crash: the kernel will branch to the padding bytes as the start of the dynamically-allocated page, and as those bytes are zero they will decode as UDF #0, which reliably triggers an UNDEFINED exception. For example: | # ./kexec --reuse-cmdline -f Image | [ 46.965800] kexec_core: Starting new kernel | [ 47.143641] psci: CPU1 killed (polled 0 ms) | [ 47.233653] psci: CPU2 killed (polled 0 ms) | [ 47.323465] psci: CPU3 killed (polled 0 ms) | [ 47.324776] Bye! | [ 47.327072] Internal error: Oops - Undefined instruction: 0000000002000000 [#1] SMP | [ 47.328510] Modules linked in: | [ 47.329086] CPU: 0 PID: 259 Comm: kexec Not tainted 6.2.0-rc5+ #3 | [ 47.330223] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015 | [ 47.331497] pstate: 604003c5 (nZCv DAIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) | [ 47.332782] pc : 0x43a95000 | [ 47.333338] lr : machine_kexec+0x190/0x1e0 | [ 47.334169] sp : ffff80000d293b70 | [ 47.334845] x29: ffff80000d293b70 x28: ffff000002cc0000 x27: 0000000000000000 | [ 47.336292] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 | [ 47.337744] x23: ffff80000a837858 x22: 0000000048ec9000 x21: 0000000000000010 | [ 47.339192] x20: 00000000adc83000 x19: ffff000000827000 x18: 0000000000000006 | [ 47.340638] x17: ffff800075a61000 x16: ffff800008000000 x15: ffff80000d293658 | [ 47.342085] x14: 0000000000000000 x13: ffff80000d2937f7 x12: ffff80000a7ff6e0 | [ 47.343530] x11: 00000000ffffdfff x10: ffff80000a8ef8e0 x9 : ffff80000813ef00 | [ 47.344976] x8 : 000000000002ffe8 x7 : c0000000ffffdfff x6 : 00000000000affa8 | [ 47.346431] x5 : 0000000000001fff x4 : 0000000000000001 x3 : ffff80000a0a3008 | [ 47.347877] x2 : ffff80000a8220f8 x1 : 0000000043a95000 x0 : ffff000000827000 | [ 47.349334] Call trace: | [ 47.349834] 0x43a95000 | [ 47.350338] kernel_kexec+0x88/0x100 | [ 47.351070] __do_sys_reboot+0x108/0x268 | [ 47.351873] __arm64_sys_reboot+0x2c/0x40 | [ 47.352689] invoke_syscall+0x78/0x108 | [ 47.353458] el0_svc_common.constprop.0+0x4c/0x100 | [ 47.354426] do_el0_svc+0x34/0x50 | [ 47.355102] el0_svc+0x34/0x108 | [ 47.355747] el0t_64_sync_handler+0xf4/0x120 | [ 47.356617] el0t_64_sync+0x194/0x198 | [ 47.357374] Code: bad PC value | [ 47.357999] ---[ end trace 0000000000000000 ]--- | [ 47.358937] Kernel panic - not syncing: Oops - Undefined instruction: Fatal exception | [ 47.360515] Kernel Offset: disabled | [ 47.361230] CPU features: 0x002000,00050108,c8004203 | [ 47.362232] Memory Limit: none Note: Unfortunately the code dump reports "bad PC value" as it attempts to dump some instructions prior to the UDF (i.e. before the start of the page), and terminates early upon a fault, obscuring the problem. This patch fixes this issue by aligning the section starter markes to CONFIG_FUNCTION_ALIGNMENT using the ALIGN_FUNCTION() helper, which ensures that the linker never needs to place padding bytes within the section. Assertions are added to verify each section begins with the function we expect, making our implicit requirement explicit. In future it might be nice to rework the kexec and hibernation code to decouple the section start from the entry point, but that involves much more significant changes that come with a higher risk of error, so I've tried to keep this fix as simple as possible for now. Fixes: 47a15aa ("arm64: Extend support for CONFIG_FUNCTION_ALIGNMENT") Reported-by: CKI Project <[email protected]> Link: https://lore.kernel.org/linux-arm-kernel/[email protected]/ Signed-off-by: Mark Rutland <[email protected]> Cc: James Morse <[email protected]> Cc: Will Deacon <[email protected]> Reviewed-by: Ard Biesheuvel <[email protected]> Signed-off-by: Catalin Marinas <[email protected]> Signed-off-by: Jerome Marchand <[email protected]>
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[ Upstream commit 9e62280 ] This fixes the following UFA in hci_acl_create_conn_sync where a connection still pending is command submission (conn->state == BT_OPEN) maybe freed, also since this also can happen with the likes of hci_le_create_conn_sync fix it as well: BUG: KASAN: slab-use-after-free in hci_acl_create_conn_sync+0x5ef/0x790 net/bluetooth/hci_sync.c:6861 Write of size 2 at addr ffff88805ffcc038 by task kworker/u11:2/9541 CPU: 1 UID: 0 PID: 9541 Comm: kworker/u11:2 Not tainted 6.16.0-rc7 #3 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Workqueue: hci3 hci_cmd_sync_work Call Trace: <TASK> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x230 mm/kasan/report.c:480 kasan_report+0x118/0x150 mm/kasan/report.c:593 hci_acl_create_conn_sync+0x5ef/0x790 net/bluetooth/hci_sync.c:6861 hci_cmd_sync_work+0x210/0x3a0 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 123736: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] __hci_conn_add+0x233/0x1b30 net/bluetooth/hci_conn.c:939 hci_conn_add_unset net/bluetooth/hci_conn.c:1051 [inline] hci_connect_acl+0x16c/0x4e0 net/bluetooth/hci_conn.c:1634 pair_device+0x418/0xa70 net/bluetooth/mgmt.c:3556 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:727 sock_write_iter+0x258/0x330 net/socket.c:1131 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x54b/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 103680: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 device_release+0x9c/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x22b/0x480 lib/kobject.c:737 hci_conn_cleanup net/bluetooth/hci_conn.c:175 [inline] hci_conn_del+0x8ff/0xcb0 net/bluetooth/hci_conn.c:1173 hci_conn_complete_evt+0x3c7/0x1040 net/bluetooth/hci_event.c:3199 hci_event_func net/bluetooth/hci_event.c:7477 [inline] hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 insert_work+0x3d/0x330 kernel/workqueue.c:2183 __queue_work+0xbd9/0xfe0 kernel/workqueue.c:2345 queue_delayed_work_on+0x18b/0x280 kernel/workqueue.c:2561 pairing_complete+0x1e7/0x2b0 net/bluetooth/mgmt.c:3451 pairing_complete_cb+0x1ac/0x230 net/bluetooth/mgmt.c:3487 hci_connect_cfm include/net/bluetooth/hci_core.h:2064 [inline] hci_conn_failed+0x24d/0x310 net/bluetooth/hci_conn.c:1275 hci_conn_complete_evt+0x3c7/0x1040 net/bluetooth/hci_event.c:3199 hci_event_func net/bluetooth/hci_event.c:7477 [inline] hci_event_packet+0x7e0/0x1200 net/bluetooth/hci_event.c:7531 hci_rx_work+0x46a/0xe80 net/bluetooth/hci_core.c:4070 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 home/kwqcheii/source/fuzzing/kernel/kasan/linux-6.16-rc7/arch/x86/entry/entry_64.S:245 Fixes: aef2aa4 ("Bluetooth: hci_event: Fix creating hci_conn object on error status") Reported-by: Junvyyang, Tencent Zhuque Lab <[email protected]> Signed-off-by: Luiz Augusto von Dentz <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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generic/091 may fail, then it bisects to the bad commit ba8dac3 ("f2fs: fix to zero post-eof page"). What will cause generic/091 to fail is something like below Testcase #1: 1. write 16k as compressed blocks 2. truncate to 12k 3. truncate to 20k 4. verify data in range of [12k, 16k], however data is not zero as expected Script of Testcase #1 mkfs.f2fs -f -O extra_attr,compression /dev/vdb mount -t f2fs -o compress_extension=* /dev/vdb /mnt/f2fs dd if=/dev/zero of=/mnt/f2fs/file bs=12k count=1 dd if=/dev/random of=/mnt/f2fs/file bs=4k count=1 seek=3 conv=notrunc sync truncate -s $((12*1024)) /mnt/f2fs/file truncate -s $((20*1024)) /mnt/f2fs/file dd if=/mnt/f2fs/file of=/mnt/f2fs/data bs=4k count=1 skip=3 od /mnt/f2fs/data umount /mnt/f2fs Analisys: in step 2), we will redirty all data pages from #0 to #3 in compressed cluster, and zero page #3, in step 3), f2fs_setattr() will call f2fs_zero_post_eof_page() to drop all page cache post eof, includeing dirtied page #3, in step 4) when we read data from page #3, it will decompressed cluster and extra random data to page #3, finally, we hit the non-zeroed data post eof. However, the commit ba8dac3 ("f2fs: fix to zero post-eof page") just let the issue be reproduced easily, w/o the commit, it can reproduce this bug w/ below Testcase #2: 1. write 16k as compressed blocks 2. truncate to 8k 3. truncate to 12k 4. truncate to 20k 5. verify data in range of [12k, 16k], however data is not zero as expected Script of Testcase #2 mkfs.f2fs -f -O extra_attr,compression /dev/vdb mount -t f2fs -o compress_extension=* /dev/vdb /mnt/f2fs dd if=/dev/zero of=/mnt/f2fs/file bs=12k count=1 dd if=/dev/random of=/mnt/f2fs/file bs=4k count=1 seek=3 conv=notrunc sync truncate -s $((8*1024)) /mnt/f2fs/file truncate -s $((12*1024)) /mnt/f2fs/file truncate -s $((20*1024)) /mnt/f2fs/file echo 3 > /proc/sys/vm/drop_caches dd if=/mnt/f2fs/file of=/mnt/f2fs/data bs=4k count=1 skip=3 od /mnt/f2fs/data umount /mnt/f2fs Anlysis: in step 2), we will redirty all data pages from #0 to #3 in compressed cluster, and zero page #2 and #3, in step 3), we will truncate page #3 in page cache, in step 4), expand file size, in step 5), hit random data post eof w/ the same reason in Testcase #1. Root Cause: In f2fs_truncate_partial_cluster(), after we truncate partial data block on compressed cluster, all pages in cluster including the one post eof will be dirtied, after another tuncation, dirty page post eof will be dropped, however on-disk compressed cluster is still valid, it may include non-zero data post eof, result in exposing previous non-zero data post eof while reading. Fix: In f2fs_truncate_partial_cluster(), let change as below to fix: - call filemap_write_and_wait_range() to flush dirty page - call truncate_pagecache() to drop pages or zero partial page post eof - call f2fs_do_truncate_blocks() to truncate non-compress cluster to last valid block Fixes: 3265d3d ("f2fs: support partial truncation on compressed inode") Reported-by: Jan Prusakowski <[email protected]> Signed-off-by: Chao Yu <[email protected]> Signed-off-by: Jaegeuk Kim <[email protected]>
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We're generally not proponents of rewrites (nasty uncomfortable things that make you late for dinner!). So why rewrite Binder? Binder has been evolving over the past 15+ years to meet the evolving needs of Android. Its responsibilities, expectations, and complexity have grown considerably during that time. While we expect Binder to continue to evolve along with Android, there are a number of factors that currently constrain our ability to develop/maintain it. Briefly those are: 1. Complexity: Binder is at the intersection of everything in Android and fulfills many responsibilities beyond IPC. It has become many things to many people, and due to its many features and their interactions with each other, its complexity is quite high. In just 6kLOC it must deliver transactions to the right threads. It must correctly parse and translate the contents of transactions, which can contain several objects of different types (e.g., pointers, fds) that can interact with each other. It controls the size of thread pools in userspace, and ensures that transactions are assigned to threads in ways that avoid deadlocks where the threadpool has run out of threads. It must track refcounts of objects that are shared by several processes by forwarding refcount changes between the processes correctly. It must handle numerous error scenarios and it combines/nests 13 different locks, 7 reference counters, and atomic variables. Finally, It must do all of this as fast and efficiently as possible. Minor performance regressions can cause a noticeably degraded user experience. 2. Things to improve: Thousand-line functions [1], error-prone error handling [2], and confusing structure can occur as a code base grows organically. After more than a decade of development, this codebase could use an overhaul. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/android/binder.c?h=v6.5#n2896 [2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/android/binder.c?h=v6.5#n3658 3. Security critical: Binder is a critical part of Android's sandboxing strategy. Even Android's most de-privileged sandboxes (e.g. the Chrome renderer, or SW Codec) have direct access to Binder. More than just about any other component, it's important that Binder provide robust security, and itself be robust against security vulnerabilities. It's #1 (high complexity) that has made continuing to evolve Binder and resolving #2 (tech debt) exceptionally difficult without causing #3 (security issues). For Binder to continue to meet Android's needs, we need better ways to manage (and reduce!) complexity without increasing the risk. The biggest change is obviously the choice of programming language. We decided to use Rust because it directly addresses a number of the challenges within Binder that we have faced during the last years. It prevents mistakes with ref counting, locking, bounds checking, and also does a lot to reduce the complexity of error handling. Additionally, we've been able to use the more expressive type system to encode the ownership semantics of the various structs and pointers, which takes the complexity of managing object lifetimes out of the hands of the programmer, reducing the risk of use-after-frees and similar problems. Rust has many different pointer types that it uses to encode ownership semantics into the type system, and this is probably one of the most important aspects of how it helps in Binder. The Binder driver has a lot of different objects that have complex ownership semantics; some pointers own a refcount, some pointers have exclusive ownership, and some pointers just reference the object and it is kept alive in some other manner. With Rust, we can use a different pointer type for each kind of pointer, which enables the compiler to enforce that the ownership semantics are implemented correctly. Another useful feature is Rust's error handling. Rust allows for more simplified error handling with features such as destructors, and you get compilation failures if errors are not properly handled. This means that even though Rust requires you to spend more lines of code than C on things such as writing down invariants that are left implicit in C, the Rust driver is still slightly smaller than C binder: Rust is 5.5kLOC and C is 5.8kLOC. (These numbers are excluding blank lines, comments, binderfs, and any debugging facilities in C that are not yet implemented in the Rust driver. The numbers include abstractions in rust/kernel/ that are unlikely to be used by other drivers than Binder.) Although this rewrite completely rethinks how the code is structured and how assumptions are enforced, we do not fundamentally change *how* the driver does the things it does. A lot of careful thought has gone into the existing design. The rewrite is aimed rather at improving code health, structure, readability, robustness, security, maintainability and extensibility. We also include more inline documentation, and improve how assumptions in the code are enforced. Furthermore, all unsafe code is annotated with a SAFETY comment that explains why it is correct. We have left the binderfs filesystem component in C. Rewriting it in Rust would be a large amount of work and requires a lot of bindings to the file system interfaces. Binderfs has not historically had the same challenges with security and complexity, so rewriting binderfs seems to have lower value than the rest of Binder. Correctness and feature parity ------------------------------ Rust binder passes all tests that validate the correctness of Binder in the Android Open Source Project. We can boot a device, and run a variety of apps and functionality without issues. We have performed this both on the Cuttlefish Android emulator device, and on a Pixel 6 Pro. As for feature parity, Rust binder currently implements all features that C binder supports, with the exception of some debugging facilities. The missing debugging facilities will be added before we submit the Rust implementation upstream. Tracepoints ----------- I did not include all of the tracepoints as I felt that the mechansim for making C access fields of Rust structs should be discussed on list separately. I also did not include the support for building Rust Binder as a module since that requires exporting a bunch of additional symbols on the C side. Original RFC Link with old benchmark numbers: https://lore.kernel.org/r/[email protected] Co-developed-by: Wedson Almeida Filho <[email protected]> Signed-off-by: Wedson Almeida Filho <[email protected]> Co-developed-by: Matt Gilbride <[email protected]> Signed-off-by: Matt Gilbride <[email protected]> Acked-by: Carlos Llamas <[email protected]> Acked-by: Paul Moore <[email protected]> Signed-off-by: Alice Ryhl <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
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…ux/kernel/git/kvmarm/kvmarm into HEAD KVM/arm64 changes for 6.17, round #3 - Invalidate nested MMUs upon freeing the PGD to avoid WARNs when visiting from an MMU notifier - Fixes to the TLB match process and TLB invalidation range for managing the VCNR pseudo-TLB - Prevent SPE from erroneously profiling guests due to UNKNOWN reset values in PMSCR_EL1 - Fix save/restore of host MDCR_EL2 to account for eagerly programming at vcpu_load() on VHE systems - Correct lock ordering when dealing with VGIC LPIs, avoiding scenarios where an xarray's spinlock was nested with a *raw* spinlock - Permit stage-2 read permission aborts which are possible in the case of NV depending on the guest hypervisor's stage-2 translation - Call raw_spin_unlock() instead of the internal spinlock API - Fix parameter ordering when assigning VBAR_EL1 [Pull into kvm/master to fix conflicts. - Paolo]
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Don't emulate branch instructions, e.g. CALL/RET/JMP etc., that are affected by Shadow Stacks and/or Indirect Branch Tracking when said features are enabled in the guest, as fully emulating CET would require significant complexity for no practical benefit (KVM shouldn't need to emulate branch instructions on modern hosts). Simply doing nothing isn't an option as that would allow a malicious entity to subvert CET protections via the emulator. To detect instructions that are subject to IBT or affect IBT state, use the existing IsBranch flag along with the source operand type to detect indirect branches, and the existing NearBranch flag to detect far JMPs and CALLs, all of which are effectively indirect. Explicitly check for emulation of IRET, FAR RET (IMM), and SYSEXIT (the ret-like far branches) instead of adding another flag, e.g. IsRet, as it's unlikely the emulator will ever need to check for return-like instructions outside of this one specific flow. Use an allow-list instead of a deny-list because (a) it's a shorter list and (b) so that a missed entry gets a false positive, not a false negative (i.e. reject emulation instead of clobbering CET state). For Shadow Stacks, explicitly track instructions that directly affect the current SSP, as KVM's emulator doesn't have existing flags that can be used to precisely detect such instructions. Alternatively, the em_xxx() helpers could directly check for ShadowStack interactions, but using a dedicated flag is arguably easier to audit, and allows for handling both IBT and SHSTK in one fell swoop. Note! On far transfers, do NOT consult the current privilege level and instead treat SHSTK/IBT as being enabled if they're enabled for User *or* Supervisor mode. On inter-privilege level far transfers, SHSTK and IBT can be in play for the target privilege level, i.e. checking the current privilege could get a false negative, and KVM doesn't know the target privilege level until emulation gets under way. Note #2, FAR JMP from 64-bit mode to compatibility mode interacts with the current SSP, but only to ensure SSP[63:32] == 0. Don't tag FAR JMP as SHSTK, which would be rather confusing and would result in FAR JMP being rejected unnecessarily the vast majority of the time (ignoring that it's unlikely to ever be emulated). A future commit will add the #GP(0) check for the specific FAR JMP scenario. Note #3, task switches also modify SSP and so need to be rejected. That too will be addressed in a future commit. Suggested-by: Chao Gao <[email protected]> Originally-by: Yang Weijiang <[email protected]> Cc: Mathias Krause <[email protected]> Cc: John Allen <[email protected]> Cc: Rick Edgecombe <[email protected]> Reviewed-by: Chao Gao <[email protected]> Reviewed-by: Binbin Wu <[email protected]> Reviewed-by: Xiaoyao Li <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sean Christopherson <[email protected]>
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Before disabling SR-IOV via config space accesses to the parent PF, sriov_disable() first removes the PCI devices representing the VFs. Since commit 9d16947 ("PCI: Add global pci_lock_rescan_remove()") such removal operations are serialized against concurrent remove and rescan using the pci_rescan_remove_lock. No such locking was ever added in sriov_disable() however. In particular when commit 18f9e9d ("PCI/IOV: Factor out sriov_add_vfs()") factored out the PCI device removal into sriov_del_vfs() there was still no locking around the pci_iov_remove_virtfn() calls. On s390 the lack of serialization in sriov_disable() may cause double remove and list corruption with the below (amended) trace being observed: PSW: 0704c00180000000 0000000c914e4b38 (klist_put+56) GPRS: 000003800313fb48 0000000000000000 0000000100000001 0000000000000001 00000000f9b520a8 0000000000000000 0000000000002fbd 00000000f4cc9480 0000000000000001 0000000000000000 0000000000000000 0000000180692828 00000000818e8000 000003800313fe2c 000003800313fb20 000003800313fad8 #0 [3800313fb20] device_del at c9158ad5c #1 [3800313fb88] pci_remove_bus_device at c915105ba #2 [3800313fbd0] pci_iov_remove_virtfn at c9152f198 #3 [3800313fc28] zpci_iov_remove_virtfn at c90fb67c0 #4 [3800313fc60] zpci_bus_remove_device at c90fb6104 #5 [3800313fca0] __zpci_event_availability at c90fb3dca #6 [3800313fd08] chsc_process_sei_nt0 at c918fe4a2 #7 [3800313fd60] crw_collect_info at c91905822 #8 [3800313fe10] kthread at c90feb390 #9 [3800313fe68] __ret_from_fork at c90f6aa64 #10 [3800313fe98] ret_from_fork at c9194f3f2. This is because in addition to sriov_disable() removing the VFs, the platform also generates hot-unplug events for the VFs. This being the reverse operation to the hotplug events generated by sriov_enable() and handled via pdev->no_vf_scan. And while the event processing takes pci_rescan_remove_lock and checks whether the struct pci_dev still exists, the lack of synchronization makes this checking racy. Other races may also be possible of course though given that this lack of locking persisted so long observable races seem very rare. Even on s390 the list corruption was only observed with certain devices since the platform events are only triggered by config accesses after the removal, so as long as the removal finished synchronously they would not race. Either way the locking is missing so fix this by adding it to the sriov_del_vfs() helper. Just like PCI rescan-remove, locking is also missing in sriov_add_vfs() including for the error case where pci_stop_and_remove_bus_device() is called without the PCI rescan-remove lock being held. Even in the non-error case, adding new PCI devices and buses should be serialized via the PCI rescan-remove lock. Add the necessary locking. Fixes: 18f9e9d ("PCI/IOV: Factor out sriov_add_vfs()") Signed-off-by: Niklas Schnelle <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Reviewed-by: Benjamin Block <[email protected]> Reviewed-by: Farhan Ali <[email protected]> Reviewed-by: Julian Ruess <[email protected]> Cc: [email protected] Link: https://patch.msgid.link/[email protected]
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The ns_bpf_qdisc selftest triggers a kernel panic: Oops[#1]: CPU 0 Unable to handle kernel paging request at virtual address 0000000000741d58, era == 90000000851b5ac0, ra == 90000000851b5aa4 CPU: 0 UID: 0 PID: 449 Comm: test_progs Tainted: G OE 6.16.0+ #3 PREEMPT(full) Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022 pc 90000000851b5ac0 ra 90000000851b5aa4 tp 90000001076b8000 sp 90000001076bb600 a0 0000000000741ce8 a1 0000000000000001 a2 90000001076bb5c0 a3 0000000000000008 a4 90000001004c4620 a5 9000000100741ce8 a6 0000000000000000 a7 0100000000000000 t0 0000000000000010 t1 0000000000000000 t2 9000000104d24d30 t3 0000000000000001 t4 4f2317da8a7e08c4 t5 fffffefffc002f00 t6 90000001004c4620 t7 ffffffffc61c5b3d t8 0000000000000000 u0 0000000000000001 s9 0000000000000050 s0 90000001075bc800 s1 0000000000000040 s2 900000010597c400 s3 0000000000000008 s4 90000001075bc880 s5 90000001075bc8f0 s6 0000000000000000 s7 0000000000741ce8 s8 0000000000000000 ra: 90000000851b5aa4 __qdisc_run+0xac/0x8d8 ERA: 90000000851b5ac0 __qdisc_run+0xc8/0x8d8 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000007 (+FPE +SXE +ASXE -BTE) ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) ESTAT: 00010000 [PIL] (IS= ECode=1 EsubCode=0) BADV: 0000000000741d58 PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) Modules linked in: bpf_testmod(OE) [last unloaded: bpf_testmod(OE)] Process test_progs (pid: 449, threadinfo=000000009af02b3a, task=00000000e9ba4956) Stack : 0000000000000000 90000001075bc8ac 90000000869524a8 9000000100741ce8 90000001075bc800 9000000100415300 90000001075bc8ac 0000000000000000 900000010597c400 900000008694a000 0000000000000000 9000000105b59000 90000001075bc800 9000000100741ce8 0000000000000050 900000008513000c 9000000086936000 0000000100094d4c fffffff400676208 0000000000000000 9000000105b59000 900000008694a000 9000000086bf0dc0 9000000105b59000 9000000086bf0d68 9000000085147010 90000001075be788 0000000000000000 9000000086bf0f98 0000000000000001 0000000000000010 9000000006015840 0000000000000000 9000000086be6c40 0000000000000000 0000000000000000 0000000000000000 4f2317da8a7e08c4 0000000000000101 4f2317da8a7e08c4 ... Call Trace: [<90000000851b5ac0>] __qdisc_run+0xc8/0x8d8 [<9000000085130008>] __dev_queue_xmit+0x578/0x10f0 [<90000000853701c0>] ip6_finish_output2+0x2f0/0x950 [<9000000085374bc8>] ip6_finish_output+0x2b8/0x448 [<9000000085370b24>] ip6_xmit+0x304/0x858 [<90000000853c4438>] inet6_csk_xmit+0x100/0x170 [<90000000852b32f0>] __tcp_transmit_skb+0x490/0xdd0 [<90000000852b47fc>] tcp_connect+0xbcc/0x1168 [<90000000853b9088>] tcp_v6_connect+0x580/0x8a0 [<90000000852e7738>] __inet_stream_connect+0x170/0x480 [<90000000852e7a98>] inet_stream_connect+0x50/0x88 [<90000000850f2814>] __sys_connect+0xe4/0x110 [<90000000850f2858>] sys_connect+0x18/0x28 [<9000000085520c94>] do_syscall+0x94/0x1a0 [<9000000083df1fb8>] handle_syscall+0xb8/0x158 Code: 4001ad80 2400873f 2400832d <240073cc> 001137ff 001133ff 6407b41f 001503cc 0280041d ---[ end trace 0000000000000000 ]--- The bpf_fifo_dequeue prog returns a skb which is a pointer. The pointer is treated as a 32bit value and sign extend to 64bit in epilogue. This behavior is right for most bpf prog types but wrong for struct ops which requires LoongArch ABI. So let's sign extend struct ops return values according to the LoongArch ABI ([1]) and return value spec in function model. [1]: https://loongson.github.io/LoongArch-Documentation/LoongArch-ELF-ABI-EN.html Cc: [email protected] Fixes: 6abf17d ("LoongArch: BPF: Add struct ops support for trampoline") Signed-off-by: Hengqi Chen <[email protected]> Signed-off-by: Huacai Chen <[email protected]>
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…uctions JIRA: https://issues.redhat.com/browse/RHEL-78202 commit ff3afe5 Author: Peilin Ye <[email protected]> Date: Tue Mar 4 01:06:46 2025 +0000 selftests/bpf: Add selftests for load-acquire and store-release instructions Add several ./test_progs tests: - arena_atomics/load_acquire - arena_atomics/store_release - verifier_load_acquire/* - verifier_store_release/* - verifier_precision/bpf_load_acquire - verifier_precision/bpf_store_release The last two tests are added to check if backtrack_insn() handles the new instructions correctly. Additionally, the last test also makes sure that the verifier "remembers" the value (in src_reg) we store-release into e.g. a stack slot. For example, if we take a look at the test program: #0: r1 = 8; /* store_release((u64 *)(r10 - 8), r1); */ #1: .8byte %[store_release]; #2: r1 = *(u64 *)(r10 - 8); #3: r2 = r10; #4: r2 += r1; #5: r0 = 0; #6: exit; At #1, if the verifier doesn't remember that we wrote 8 to the stack, then later at #4 we would be adding an unbounded scalar value to the stack pointer, which would cause the program to be rejected: VERIFIER LOG: ============= ... math between fp pointer and register with unbounded min value is not allowed For easier CI integration, instead of using built-ins like __atomic_{load,store}_n() which depend on the new __BPF_FEATURE_LOAD_ACQ_STORE_REL pre-defined macro, manually craft load-acquire/store-release instructions using __imm_insn(), as suggested by Eduard. All new tests depend on: (1) Clang major version >= 18, and (2) ENABLE_ATOMICS_TESTS is defined (currently implies -mcpu=v3 or v4), and (3) JIT supports load-acquire/store-release (currently arm64 and x86-64) In .../progs/arena_atomics.c: /* 8-byte-aligned */ __u8 __arena_global load_acquire8_value = 0x12; /* 1-byte hole */ __u16 __arena_global load_acquire16_value = 0x1234; That 1-byte hole in the .addr_space.1 ELF section caused clang-17 to crash: fatal error: error in backend: unable to write nop sequence of 1 bytes To work around such llvm-17 CI job failures, conditionally define __arena_global variables as 64-bit if __clang_major__ < 18, to make sure .addr_space.1 has no holes. Ideally we should avoid compiling this file using clang-17 at all (arena tests depend on __BPF_FEATURE_ADDR_SPACE_CAST, and are skipped for llvm-17 anyway), but that is a separate topic. Acked-by: Eduard Zingerman <[email protected]> Signed-off-by: Peilin Ye <[email protected]> Link: https://lore.kernel.org/r/1b46c6feaf0f1b6984d9ec80e500cc7383e9da1a.1741049567.git.yepeilin@google.com Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Gregory Bell <[email protected]>
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The test starts a workload and then opens events. If the events fail
to open, for example because of perf_event_paranoid, the gopipe of the
workload is leaked and the file descriptor leak check fails when the
test exits. To avoid this cancel the workload when opening the events
fails.
Before:
```
$ perf test -vv 7
7: PERF_RECORD_* events & perf_sample fields:
--- start ---
test child forked, pid 1189568
Using CPUID GenuineIntel-6-B7-1
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/)
disabled 1
------------------------------------------------------------
sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8
sys_perf_event_open failed, error -13
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/)
disabled 1
exclude_kernel 1
------------------------------------------------------------
sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/)
disabled 1
------------------------------------------------------------
sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8
sys_perf_event_open failed, error -13
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/)
disabled 1
exclude_kernel 1
------------------------------------------------------------
sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3
Attempt to add: software/cpu-clock/
..after resolving event: software/config=0/
cpu-clock -> software/cpu-clock/
------------------------------------------------------------
perf_event_attr:
type 1 (PERF_TYPE_SOFTWARE)
size 136
config 0x9 (PERF_COUNT_SW_DUMMY)
sample_type IP|TID|TIME|CPU
read_format ID|LOST
disabled 1
inherit 1
mmap 1
comm 1
enable_on_exec 1
task 1
sample_id_all 1
mmap2 1
comm_exec 1
ksymbol 1
bpf_event 1
{ wakeup_events, wakeup_watermark } 1
------------------------------------------------------------
sys_perf_event_open: pid 1189569 cpu 0 group_fd -1 flags 0x8
sys_perf_event_open failed, error -13
perf_evlist__open: Permission denied
---- end(-2) ----
Leak of file descriptor 6 that opened: 'pipe:[14200347]'
---- unexpected signal (6) ----
iFailed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
Failed to read build ID for //anon
#0 0x565358f6666e in child_test_sig_handler builtin-test.c:311
#1 0x7f29ce849df0 in __restore_rt libc_sigaction.c:0
#2 0x7f29ce89e95c in __pthread_kill_implementation pthread_kill.c:44
#3 0x7f29ce849cc2 in raise raise.c:27
#4 0x7f29ce8324ac in abort abort.c:81
#5 0x565358f662d4 in check_leaks builtin-test.c:226
#6 0x565358f6682e in run_test_child builtin-test.c:344
#7 0x565358ef7121 in start_command run-command.c:128
#8 0x565358f67273 in start_test builtin-test.c:545
#9 0x565358f6771d in __cmd_test builtin-test.c:647
#10 0x565358f682bd in cmd_test builtin-test.c:849
#11 0x565358ee5ded in run_builtin perf.c:349
#12 0x565358ee6085 in handle_internal_command perf.c:401
#13 0x565358ee61de in run_argv perf.c:448
#14 0x565358ee6527 in main perf.c:555
#15 0x7f29ce833ca8 in __libc_start_call_main libc_start_call_main.h:74
#16 0x7f29ce833d65 in __libc_start_main@@GLIBC_2.34 libc-start.c:128
#17 0x565358e391c1 in _start perf[851c1]
7: PERF_RECORD_* events & perf_sample fields : FAILED!
```
After:
```
$ perf test 7
7: PERF_RECORD_* events & perf_sample fields : Skip (permissions)
```
Fixes: 16d00fe ("perf tests: Move test__PERF_RECORD into separate object")
Signed-off-by: Ian Rogers <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Chun-Tse Shao <[email protected]>
Cc: Howard Chu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
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jira LE-4365 Rebuild_History Non-Buildable kernel-6.12.0-55.38.1.el10_0 commit-author Haiyang Zhang <[email protected]> commit 33caa20 The existing code move the VF NIC to new namespace when NETDEV_REGISTER is received on netvsc NIC. During deletion of the namespace, default_device_exit_batch() >> default_device_exit_net() is called. When netvsc NIC is moved back and registered to the default namespace, it automatically brings VF NIC back to the default namespace. This will cause the default_device_exit_net() >> for_each_netdev_safe loop unable to detect the list end, and hit NULL ptr: [ 231.449420] mana 7870:00:00.0 enP30832s1: Moved VF to namespace with: eth0 [ 231.449656] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 231.450246] #PF: supervisor read access in kernel mode [ 231.450579] #PF: error_code(0x0000) - not-present page [ 231.450916] PGD 17b8a8067 P4D 0 [ 231.451163] Oops: Oops: 0000 [#1] SMP NOPTI [ 231.451450] CPU: 82 UID: 0 PID: 1394 Comm: kworker/u768:1 Not tainted 6.16.0-rc4+ #3 VOLUNTARY [ 231.452042] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/21/2024 [ 231.452692] Workqueue: netns cleanup_net [ 231.452947] RIP: 0010:default_device_exit_batch+0x16c/0x3f0 [ 231.453326] Code: c0 0c f5 b3 e8 d5 db fe ff 48 85 c0 74 15 48 c7 c2 f8 fd ca b2 be 10 00 00 00 48 8d 7d c0 e8 7b 77 25 00 49 8b 86 28 01 00 00 <48> 8b 50 10 4c 8b 2a 4c 8d 62 f0 49 83 ed 10 4c 39 e0 0f 84 d6 00 [ 231.454294] RSP: 0018:ff75fc7c9bf9fd00 EFLAGS: 00010246 [ 231.454610] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 61c8864680b583eb [ 231.455094] RDX: ff1fa9f71462d800 RSI: ff75fc7c9bf9fd38 RDI: 0000000030766564 [ 231.455686] RBP: ff75fc7c9bf9fd78 R08: 0000000000000000 R09: 0000000000000000 [ 231.456126] R10: 0000000000000001 R11: 0000000000000004 R12: ff1fa9f70088e340 [ 231.456621] R13: ff1fa9f70088e340 R14: ffffffffb3f50c20 R15: ff1fa9f7103e6340 [ 231.457161] FS: 0000000000000000(0000) GS:ff1faa6783a08000(0000) knlGS:0000000000000000 [ 231.457707] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 231.458031] CR2: 0000000000000010 CR3: 0000000179ab2006 CR4: 0000000000b73ef0 [ 231.458434] Call Trace: [ 231.458600] <TASK> [ 231.458777] ops_undo_list+0x100/0x220 [ 231.459015] cleanup_net+0x1b8/0x300 [ 231.459285] process_one_work+0x184/0x340 To fix it, move the ns change to a workqueue, and take rtnl_lock to avoid changing the netdev list when default_device_exit_net() is using it. Cc: [email protected] Fixes: 4c26280 ("hv_netvsc: Fix VF namespace also in synthetic NIC NETDEV_REGISTER event") Signed-off-by: Haiyang Zhang <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> (cherry picked from commit 33caa20) Signed-off-by: Jonathan Maple <[email protected]>
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jira LE-4385 Rebuild_History Non-Buildable kernel-5.14.0-570.52.1.el9_6 commit-author Haiyang Zhang <[email protected]> commit 33caa20 The existing code move the VF NIC to new namespace when NETDEV_REGISTER is received on netvsc NIC. During deletion of the namespace, default_device_exit_batch() >> default_device_exit_net() is called. When netvsc NIC is moved back and registered to the default namespace, it automatically brings VF NIC back to the default namespace. This will cause the default_device_exit_net() >> for_each_netdev_safe loop unable to detect the list end, and hit NULL ptr: [ 231.449420] mana 7870:00:00.0 enP30832s1: Moved VF to namespace with: eth0 [ 231.449656] BUG: kernel NULL pointer dereference, address: 0000000000000010 [ 231.450246] #PF: supervisor read access in kernel mode [ 231.450579] #PF: error_code(0x0000) - not-present page [ 231.450916] PGD 17b8a8067 P4D 0 [ 231.451163] Oops: Oops: 0000 [#1] SMP NOPTI [ 231.451450] CPU: 82 UID: 0 PID: 1394 Comm: kworker/u768:1 Not tainted 6.16.0-rc4+ #3 VOLUNTARY [ 231.452042] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 11/21/2024 [ 231.452692] Workqueue: netns cleanup_net [ 231.452947] RIP: 0010:default_device_exit_batch+0x16c/0x3f0 [ 231.453326] Code: c0 0c f5 b3 e8 d5 db fe ff 48 85 c0 74 15 48 c7 c2 f8 fd ca b2 be 10 00 00 00 48 8d 7d c0 e8 7b 77 25 00 49 8b 86 28 01 00 00 <48> 8b 50 10 4c 8b 2a 4c 8d 62 f0 49 83 ed 10 4c 39 e0 0f 84 d6 00 [ 231.454294] RSP: 0018:ff75fc7c9bf9fd00 EFLAGS: 00010246 [ 231.454610] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 61c8864680b583eb [ 231.455094] RDX: ff1fa9f71462d800 RSI: ff75fc7c9bf9fd38 RDI: 0000000030766564 [ 231.455686] RBP: ff75fc7c9bf9fd78 R08: 0000000000000000 R09: 0000000000000000 [ 231.456126] R10: 0000000000000001 R11: 0000000000000004 R12: ff1fa9f70088e340 [ 231.456621] R13: ff1fa9f70088e340 R14: ffffffffb3f50c20 R15: ff1fa9f7103e6340 [ 231.457161] FS: 0000000000000000(0000) GS:ff1faa6783a08000(0000) knlGS:0000000000000000 [ 231.457707] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 231.458031] CR2: 0000000000000010 CR3: 0000000179ab2006 CR4: 0000000000b73ef0 [ 231.458434] Call Trace: [ 231.458600] <TASK> [ 231.458777] ops_undo_list+0x100/0x220 [ 231.459015] cleanup_net+0x1b8/0x300 [ 231.459285] process_one_work+0x184/0x340 To fix it, move the ns change to a workqueue, and take rtnl_lock to avoid changing the netdev list when default_device_exit_net() is using it. Cc: [email protected] Fixes: 4c26280 ("hv_netvsc: Fix VF namespace also in synthetic NIC NETDEV_REGISTER event") Signed-off-by: Haiyang Zhang <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> (cherry picked from commit 33caa20) Signed-off-by: Jonathan Maple <[email protected]>
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Since blamed commit, unregister_netdevice_many_notify() takes the netdev
mutex if the device needs it.
If the device list is too long, this will lock more device mutexes than
lockdep can handle:
unshare -n \
bash -c 'for i in $(seq 1 100);do ip link add foo$i type dummy;done'
BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48 max: 48!
48 locks held by kworker/u16:1/69:
#0: ..148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work
#1: ..d40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work
#2: ..bd0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net
#3: ..aa8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch
#4: ..cb0 (&dev_instance_lock_key#3){+.+.}-{4:4}, at: unregister_netdevice_many_notify
[..]
Add a helper to close and then unlock a list of net_devices.
Devices that are not up have to be skipped - netif_close_many always
removes them from the list without any other actions taken, so they'd
remain in locked state.
Close devices whenever we've used up half of the tracking slots or we
processed entire list without hitting the limit.
Fixes: 7e4d784 ("net: hold netdev instance lock during rtnetlink operations")
Signed-off-by: Florian Westphal <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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Expand the prefault memory selftest to add a regression test for a KVM bug where KVM's retry logic would result in (breakable) deadlock due to the memslot deletion waiting on prefaulting to release SRCU, and prefaulting waiting on the memslot to fully disappear (KVM uses a two-step process to delete memslots, and KVM x86 retries page faults if a to-be-deleted, a.k.a. INVALID, memslot is encountered). To exercise concurrent memslot remove, spawn a second thread to initiate memslot removal at roughly the same time as prefaulting. Test memslot removal for all testcases, i.e. don't limit concurrent removal to only the success case. There are essentially three prefault scenarios (so far) that are of interest: 1. Success 2. ENOENT due to no memslot 3. EAGAIN due to INVALID memslot For all intents and purposes, #1 and #2 are mutually exclusive, or rather, easier to test via separate testcases since writing to non-existent memory is trivial. But for #3, making it mutually exclusive with #1 _or_ #2 is actually more complex than testing memslot removal for all scenarios. The only requirement to let memslot removal coexist with other scenarios is a way to guarantee a stable result, e.g. that the "no memslot" test observes ENOENT, not EAGAIN, for the final checks. So, rather than make memslot removal mutually exclusive with the ENOENT scenario, simply restore the memslot and retry prefaulting. For the "no memslot" case, KVM_PRE_FAULT_MEMORY should be idempotent, i.e. should always fail with ENOENT regardless of how many times userspace attempts prefaulting. Pass in both the base GPA and the offset (instead of the "full" GPA) so that the worker can recreate the memslot. Signed-off-by: Yan Zhao <[email protected]> Co-developed-by: Sean Christopherson <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Sean Christopherson <[email protected]>
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[ Upstream commit 48918ca ] The test starts a workload and then opens events. If the events fail to open, for example because of perf_event_paranoid, the gopipe of the workload is leaked and the file descriptor leak check fails when the test exits. To avoid this cancel the workload when opening the events fails. Before: ``` $ perf test -vv 7 7: PERF_RECORD_* events & perf_sample fields: --- start --- test child forked, pid 1189568 Using CPUID GenuineIntel-6-B7-1 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0xa00000000 (cpu_atom/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 exclude_kernel 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) config 0x400000000 (cpu_core/PERF_COUNT_HW_CPU_CYCLES/) disabled 1 exclude_kernel 1 ------------------------------------------------------------ sys_perf_event_open: pid 0 cpu -1 group_fd -1 flags 0x8 = 3 Attempt to add: software/cpu-clock/ ..after resolving event: software/config=0/ cpu-clock -> software/cpu-clock/ ------------------------------------------------------------ perf_event_attr: type 1 (PERF_TYPE_SOFTWARE) size 136 config 0x9 (PERF_COUNT_SW_DUMMY) sample_type IP|TID|TIME|CPU read_format ID|LOST disabled 1 inherit 1 mmap 1 comm 1 enable_on_exec 1 task 1 sample_id_all 1 mmap2 1 comm_exec 1 ksymbol 1 bpf_event 1 { wakeup_events, wakeup_watermark } 1 ------------------------------------------------------------ sys_perf_event_open: pid 1189569 cpu 0 group_fd -1 flags 0x8 sys_perf_event_open failed, error -13 perf_evlist__open: Permission denied ---- end(-2) ---- Leak of file descriptor 6 that opened: 'pipe:[14200347]' ---- unexpected signal (6) ---- iFailed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon Failed to read build ID for //anon #0 0x565358f6666e in child_test_sig_handler builtin-test.c:311 #1 0x7f29ce849df0 in __restore_rt libc_sigaction.c:0 #2 0x7f29ce89e95c in __pthread_kill_implementation pthread_kill.c:44 #3 0x7f29ce849cc2 in raise raise.c:27 #4 0x7f29ce8324ac in abort abort.c:81 #5 0x565358f662d4 in check_leaks builtin-test.c:226 #6 0x565358f6682e in run_test_child builtin-test.c:344 #7 0x565358ef7121 in start_command run-command.c:128 #8 0x565358f67273 in start_test builtin-test.c:545 #9 0x565358f6771d in __cmd_test builtin-test.c:647 #10 0x565358f682bd in cmd_test builtin-test.c:849 #11 0x565358ee5ded in run_builtin perf.c:349 #12 0x565358ee6085 in handle_internal_command perf.c:401 #13 0x565358ee61de in run_argv perf.c:448 #14 0x565358ee6527 in main perf.c:555 #15 0x7f29ce833ca8 in __libc_start_call_main libc_start_call_main.h:74 #16 0x7f29ce833d65 in __libc_start_main@@GLIBC_2.34 libc-start.c:128 #17 0x565358e391c1 in _start perf[851c1] 7: PERF_RECORD_* events & perf_sample fields : FAILED! ``` After: ``` $ perf test 7 7: PERF_RECORD_* events & perf_sample fields : Skip (permissions) ``` Fixes: 16d00fe ("perf tests: Move test__PERF_RECORD into separate object") Signed-off-by: Ian Rogers <[email protected]> Tested-by: Arnaldo Carvalho de Melo <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Athira Rajeev <[email protected]> Cc: Chun-Tse Shao <[email protected]> Cc: Howard Chu <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: James Clark <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Kan Liang <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit 0570327 upstream. Before disabling SR-IOV via config space accesses to the parent PF, sriov_disable() first removes the PCI devices representing the VFs. Since commit 9d16947 ("PCI: Add global pci_lock_rescan_remove()") such removal operations are serialized against concurrent remove and rescan using the pci_rescan_remove_lock. No such locking was ever added in sriov_disable() however. In particular when commit 18f9e9d ("PCI/IOV: Factor out sriov_add_vfs()") factored out the PCI device removal into sriov_del_vfs() there was still no locking around the pci_iov_remove_virtfn() calls. On s390 the lack of serialization in sriov_disable() may cause double remove and list corruption with the below (amended) trace being observed: PSW: 0704c00180000000 0000000c914e4b38 (klist_put+56) GPRS: 000003800313fb48 0000000000000000 0000000100000001 0000000000000001 00000000f9b520a8 0000000000000000 0000000000002fbd 00000000f4cc9480 0000000000000001 0000000000000000 0000000000000000 0000000180692828 00000000818e8000 000003800313fe2c 000003800313fb20 000003800313fad8 #0 [3800313fb20] device_del at c9158ad5c #1 [3800313fb88] pci_remove_bus_device at c915105ba #2 [3800313fbd0] pci_iov_remove_virtfn at c9152f198 #3 [3800313fc28] zpci_iov_remove_virtfn at c90fb67c0 #4 [3800313fc60] zpci_bus_remove_device at c90fb6104 #5 [3800313fca0] __zpci_event_availability at c90fb3dca #6 [3800313fd08] chsc_process_sei_nt0 at c918fe4a2 #7 [3800313fd60] crw_collect_info at c91905822 #8 [3800313fe10] kthread at c90feb390 #9 [3800313fe68] __ret_from_fork at c90f6aa64 #10 [3800313fe98] ret_from_fork at c9194f3f2. This is because in addition to sriov_disable() removing the VFs, the platform also generates hot-unplug events for the VFs. This being the reverse operation to the hotplug events generated by sriov_enable() and handled via pdev->no_vf_scan. And while the event processing takes pci_rescan_remove_lock and checks whether the struct pci_dev still exists, the lack of synchronization makes this checking racy. Other races may also be possible of course though given that this lack of locking persisted so long observable races seem very rare. Even on s390 the list corruption was only observed with certain devices since the platform events are only triggered by config accesses after the removal, so as long as the removal finished synchronously they would not race. Either way the locking is missing so fix this by adding it to the sriov_del_vfs() helper. Just like PCI rescan-remove, locking is also missing in sriov_add_vfs() including for the error case where pci_stop_and_remove_bus_device() is called without the PCI rescan-remove lock being held. Even in the non-error case, adding new PCI devices and buses should be serialized via the PCI rescan-remove lock. Add the necessary locking. Fixes: 18f9e9d ("PCI/IOV: Factor out sriov_add_vfs()") Signed-off-by: Niklas Schnelle <[email protected]> Signed-off-by: Bjorn Helgaas <[email protected]> Reviewed-by: Benjamin Block <[email protected]> Reviewed-by: Farhan Ali <[email protected]> Reviewed-by: Julian Ruess <[email protected]> Cc: [email protected] Link: https://patch.msgid.link/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
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JIRA: https://issues.redhat.com/browse/RHEL-116007 commit cf02334 Author: Dmitry Baryshkov <[email protected]> Date: Thu, 5 Jun 2025 14:25:49 +0300 If the PHY driver uses another PHY internally (e.g. in case of eUSB2, repeaters are represented as PHYs), then it would trigger the following lockdep splat because all PHYs use a single static lockdep key and thus lockdep can not identify whether there is a dependency or not and reports a false positive. Make PHY subsystem use dynamic lockdep keys, assigning each driver a separate key. This way lockdep can correctly identify dependency graph between mutexes. ============================================ WARNING: possible recursive locking detected 6.15.0-rc7-next-20250522-12896-g3932f283970c #3455 Not tainted -------------------------------------------- kworker/u51:0/78 is trying to acquire lock: ffff0008116554f0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c but task is already holding lock: ffff000813c10cf0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&phy->mutex); lock(&phy->mutex); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by kworker/u51:0/78: #0: ffff000800010948 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x18c/0x5ec #1: ffff80008036bdb0 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1b4/0x5ec #2: ffff0008094ac8f8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x38/0x188 #3: ffff000813c10cf0 (&phy->mutex){+.+.}-{4:4}, at: phy_init+0x4c/0x12c stack backtrace: CPU: 0 UID: 0 PID: 78 Comm: kworker/u51:0 Not tainted 6.15.0-rc7-next-20250522-12896-g3932f283970c #3455 PREEMPT Hardware name: Qualcomm CRD, BIOS 6.0.240904.BOOT.MXF.2.4-00528.1-HAMOA-1 09/ 4/2024 Workqueue: events_unbound deferred_probe_work_func Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0x90/0xd0 dump_stack+0x18/0x24 print_deadlock_bug+0x258/0x348 __lock_acquire+0x10fc/0x1f84 lock_acquire+0x1c8/0x338 __mutex_lock+0xb8/0x59c mutex_lock_nested+0x24/0x30 phy_init+0x4c/0x12c snps_eusb2_hsphy_init+0x54/0x1a0 phy_init+0xe0/0x12c dwc3_core_init+0x450/0x10b4 dwc3_core_probe+0xce4/0x15fc dwc3_probe+0x64/0xb0 platform_probe+0x68/0xc4 really_probe+0xbc/0x298 __driver_probe_device+0x78/0x12c driver_probe_device+0x3c/0x160 __device_attach_driver+0xb8/0x138 bus_for_each_drv+0x84/0xe0 __device_attach+0x9c/0x188 device_initial_probe+0x14/0x20 bus_probe_device+0xac/0xb0 deferred_probe_work_func+0x8c/0xc8 process_one_work+0x208/0x5ec worker_thread+0x1c0/0x368 kthread+0x14c/0x20c ret_from_fork+0x10/0x20 Fixes: 3584f63 ("phy: qcom: phy-qcom-snps-eusb2: Add support for eUSB2 repeater") Fixes: e246355 ("phy: amlogic: Add Amlogic AXG PCIE PHY Driver") Reviewed-by: Neil Armstrong <[email protected]> Reviewed-by: Abel Vesa <[email protected]> Reported-by: Johan Hovold <[email protected]> Link: https://lore.kernel.org/lkml/[email protected]/ Reviewed-by: Johan Hovold <[email protected]> Tested-by: Johan Hovold <[email protected]> Signed-off-by: Dmitry Baryshkov <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Vinod Koul <[email protected]> Signed-off-by: Desnes Nunes <[email protected]>
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JIRA: https://issues.redhat.com/browse/RHEL-78203 commit ee684de Author: Viktor Malik <[email protected]> Date: Tue Apr 15 17:50:14 2025 +0200 libbpf: Fix buffer overflow in bpf_object__init_prog As shown in [1], it is possible to corrupt a BPF ELF file such that arbitrary BPF instructions are loaded by libbpf. This can be done by setting a symbol (BPF program) section offset to a large (unsigned) number such that <section start + symbol offset> overflows and points before the section data in the memory. Consider the situation below where: - prog_start = sec_start + symbol_offset <-- size_t overflow here - prog_end = prog_start + prog_size prog_start sec_start prog_end sec_end | | | | v v v v .....................|################################|............ The report in [1] also provides a corrupted BPF ELF which can be used as a reproducer: $ readelf -S crash Section Headers: [Nr] Name Type Address Offset Size EntSize Flags Link Info Align ... [ 2] uretprobe.mu[...] PROGBITS 0000000000000000 00000040 0000000000000068 0000000000000000 AX 0 0 8 $ readelf -s crash Symbol table '.symtab' contains 8 entries: Num: Value Size Type Bind Vis Ndx Name ... 6: ffffffffffffffb8 104 FUNC GLOBAL DEFAULT 2 handle_tp Here, the handle_tp prog has section offset ffffffffffffffb8, i.e. will point before the actual memory where section 2 is allocated. This is also reported by AddressSanitizer: ================================================================= ==1232==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x7c7302fe0000 at pc 0x7fc3046e4b77 bp 0x7ffe64677cd0 sp 0x7ffe64677490 READ of size 104 at 0x7c7302fe0000 thread T0 #0 0x7fc3046e4b76 in memcpy (/lib64/libasan.so.8+0xe4b76) #1 0x00000040df3e in bpf_object__init_prog /src/libbpf/src/libbpf.c:856 #2 0x00000040df3e in bpf_object__add_programs /src/libbpf/src/libbpf.c:928 #3 0x00000040df3e in bpf_object__elf_collect /src/libbpf/src/libbpf.c:3930 #4 0x00000040df3e in bpf_object_open /src/libbpf/src/libbpf.c:8067 #5 0x00000040f176 in bpf_object__open_file /src/libbpf/src/libbpf.c:8090 #6 0x000000400c16 in main /poc/poc.c:8 #7 0x7fc3043d25b4 in __libc_start_call_main (/lib64/libc.so.6+0x35b4) #8 0x7fc3043d2667 in __libc_start_main@@GLIBC_2.34 (/lib64/libc.so.6+0x3667) #9 0x000000400b34 in _start (/poc/poc+0x400b34) 0x7c7302fe0000 is located 64 bytes before 104-byte region [0x7c7302fe0040,0x7c7302fe00a8) allocated by thread T0 here: #0 0x7fc3046e716b in malloc (/lib64/libasan.so.8+0xe716b) #1 0x7fc3045ee600 in __libelf_set_rawdata_wrlock (/lib64/libelf.so.1+0xb600) #2 0x7fc3045ef018 in __elf_getdata_rdlock (/lib64/libelf.so.1+0xc018) #3 0x00000040642f in elf_sec_data /src/libbpf/src/libbpf.c:3740 The problem here is that currently, libbpf only checks that the program end is within the section bounds. There used to be a check `while (sec_off < sec_sz)` in bpf_object__add_programs, however, it was removed by commit 6245947 ("libbpf: Allow gaps in BPF program sections to support overriden weak functions"). Add a check for detecting the overflow of `sec_off + prog_sz` to bpf_object__init_prog to fix this issue. [1] https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Fixes: 6245947 ("libbpf: Allow gaps in BPF program sections to support overriden weak functions") Reported-by: lmarch2 <[email protected]> Signed-off-by: Viktor Malik <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Reviewed-by: Shung-Hsi Yu <[email protected]> Link: https://github.com/lmarch2/poc/blob/main/libbpf/libbpf.md Link: https://lore.kernel.org/bpf/[email protected] Signed-off-by: Viktor Malik <[email protected]>
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JIRA: https://issues.redhat.com/browse/RHEL-112997 commit ffa1e7a Author: Thomas Hellström <[email protected]> Date: Tue Mar 18 10:55:48 2025 +0100 block: Make request_queue lockdep splats show up earlier In recent kernels, there are lockdep splats around the struct request_queue::io_lockdep_map, similar to [1], but they typically don't show up until reclaim with writeback happens. Having multiple kernel versions released with a known risc of kernel deadlock during reclaim writeback should IMHO be addressed and backported to -stable with the highest priority. In order to have these lockdep splats show up earlier, preferrably during system initialization, prime the struct request_queue::io_lockdep_map as GFP_KERNEL reclaim- tainted. This will instead lead to lockdep splats looking similar to [2], but without the need for reclaim + writeback happening. [1]: [ 189.762244] ====================================================== [ 189.762432] WARNING: possible circular locking dependency detected [ 189.762441] 6.14.0-rc6-xe+ #6 Tainted: G U [ 189.762450] ------------------------------------------------------ [ 189.762459] kswapd0/119 is trying to acquire lock: [ 189.762467] ffff888110ceb710 (&q->q_usage_counter(io)#26){++++}-{0:0}, at: __submit_bio+0x76/0x230 [ 189.762485] but task is already holding lock: [ 189.762494] ffffffff834c97c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xbe/0xb00 [ 189.762507] which lock already depends on the new lock. [ 189.762519] the existing dependency chain (in reverse order) is: [ 189.762529] -> #2 (fs_reclaim){+.+.}-{0:0}: [ 189.762540] fs_reclaim_acquire+0xc5/0x100 [ 189.762548] kmem_cache_alloc_lru_noprof+0x4a/0x480 [ 189.762558] alloc_inode+0xaa/0xe0 [ 189.762566] iget_locked+0x157/0x330 [ 189.762573] kernfs_get_inode+0x1b/0x110 [ 189.762582] kernfs_get_tree+0x1b0/0x2e0 [ 189.762590] sysfs_get_tree+0x1f/0x60 [ 189.762597] vfs_get_tree+0x2a/0xf0 [ 189.762605] path_mount+0x4cd/0xc00 [ 189.762613] __x64_sys_mount+0x119/0x150 [ 189.762621] x64_sys_call+0x14f2/0x2310 [ 189.762630] do_syscall_64+0x91/0x180 [ 189.762637] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 189.762647] -> #1 (&root->kernfs_rwsem){++++}-{3:3}: [ 189.762659] down_write+0x3e/0xf0 [ 189.762667] kernfs_remove+0x32/0x60 [ 189.762676] sysfs_remove_dir+0x4f/0x60 [ 189.762685] __kobject_del+0x33/0xa0 [ 189.762709] kobject_del+0x13/0x30 [ 189.762716] elv_unregister_queue+0x52/0x80 [ 189.762725] elevator_switch+0x68/0x360 [ 189.762733] elv_iosched_store+0x14b/0x1b0 [ 189.762756] queue_attr_store+0x181/0x1e0 [ 189.762765] sysfs_kf_write+0x49/0x80 [ 189.762773] kernfs_fop_write_iter+0x17d/0x250 [ 189.762781] vfs_write+0x281/0x540 [ 189.762790] ksys_write+0x72/0xf0 [ 189.762798] __x64_sys_write+0x19/0x30 [ 189.762807] x64_sys_call+0x2a3/0x2310 [ 189.762815] do_syscall_64+0x91/0x180 [ 189.762823] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 189.762833] -> #0 (&q->q_usage_counter(io)#26){++++}-{0:0}: [ 189.762845] __lock_acquire+0x1525/0x2760 [ 189.762854] lock_acquire+0xca/0x310 [ 189.762861] blk_mq_submit_bio+0x8a2/0xba0 [ 189.762870] __submit_bio+0x76/0x230 [ 189.762878] submit_bio_noacct_nocheck+0x323/0x430 [ 189.762888] submit_bio_noacct+0x2cc/0x620 [ 189.762896] submit_bio+0x38/0x110 [ 189.762904] __swap_writepage+0xf5/0x380 [ 189.762912] swap_writepage+0x3c7/0x600 [ 189.762920] shmem_writepage+0x3da/0x4f0 [ 189.762929] pageout+0x13f/0x310 [ 189.762937] shrink_folio_list+0x61c/0xf60 [ 189.763261] evict_folios+0x378/0xcd0 [ 189.763584] try_to_shrink_lruvec+0x1b0/0x360 [ 189.763946] shrink_one+0x10e/0x200 [ 189.764266] shrink_node+0xc02/0x1490 [ 189.764586] balance_pgdat+0x563/0xb00 [ 189.764934] kswapd+0x1e8/0x430 [ 189.765249] kthread+0x10b/0x260 [ 189.765559] ret_from_fork+0x44/0x70 [ 189.765889] ret_from_fork_asm+0x1a/0x30 [ 189.766198] other info that might help us debug this: [ 189.767089] Chain exists of: &q->q_usage_counter(io)#26 --> &root->kernfs_rwsem --> fs_reclaim [ 189.767971] Possible unsafe locking scenario: [ 189.768555] CPU0 CPU1 [ 189.768849] ---- ---- [ 189.769136] lock(fs_reclaim); [ 189.769421] lock(&root->kernfs_rwsem); [ 189.769714] lock(fs_reclaim); [ 189.770016] rlock(&q->q_usage_counter(io)#26); [ 189.770305] *** DEADLOCK *** [ 189.771167] 1 lock held by kswapd0/119: [ 189.771453] #0: ffffffff834c97c0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0xbe/0xb00 [ 189.771770] stack backtrace: [ 189.772351] CPU: 4 UID: 0 PID: 119 Comm: kswapd0 Tainted: G U 6.14.0-rc6-xe+ #6 [ 189.772353] Tainted: [U]=USER [ 189.772354] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023 [ 189.772354] Call Trace: [ 189.772355] <TASK> [ 189.772356] dump_stack_lvl+0x6e/0xa0 [ 189.772359] dump_stack+0x10/0x18 [ 189.772360] print_circular_bug.cold+0x17a/0x1b7 [ 189.772363] check_noncircular+0x13a/0x150 [ 189.772365] ? __pfx_stack_trace_consume_entry+0x10/0x10 [ 189.772368] __lock_acquire+0x1525/0x2760 [ 189.772368] ? ret_from_fork_asm+0x1a/0x30 [ 189.772371] lock_acquire+0xca/0x310 [ 189.772372] ? __submit_bio+0x76/0x230 [ 189.772375] ? lock_release+0xd5/0x2c0 [ 189.772376] blk_mq_submit_bio+0x8a2/0xba0 [ 189.772378] ? __submit_bio+0x76/0x230 [ 189.772380] __submit_bio+0x76/0x230 [ 189.772382] ? trace_hardirqs_on+0x1e/0xe0 [ 189.772384] submit_bio_noacct_nocheck+0x323/0x430 [ 189.772386] ? submit_bio_noacct_nocheck+0x323/0x430 [ 189.772387] ? __might_sleep+0x58/0xa0 [ 189.772390] submit_bio_noacct+0x2cc/0x620 [ 189.772391] ? count_memcg_events+0x68/0x90 [ 189.772393] submit_bio+0x38/0x110 [ 189.772395] __swap_writepage+0xf5/0x380 [ 189.772396] swap_writepage+0x3c7/0x600 [ 189.772397] shmem_writepage+0x3da/0x4f0 [ 189.772401] pageout+0x13f/0x310 [ 189.772406] shrink_folio_list+0x61c/0xf60 [ 189.772409] ? isolate_folios+0xe80/0x16b0 [ 189.772410] ? mark_held_locks+0x46/0x90 [ 189.772412] evict_folios+0x378/0xcd0 [ 189.772414] ? evict_folios+0x34a/0xcd0 [ 189.772415] ? lock_is_held_type+0xa3/0x130 [ 189.772417] try_to_shrink_lruvec+0x1b0/0x360 [ 189.772420] shrink_one+0x10e/0x200 [ 189.772421] shrink_node+0xc02/0x1490 [ 189.772423] ? shrink_node+0xa08/0x1490 [ 189.772424] ? shrink_node+0xbd8/0x1490 [ 189.772425] ? mem_cgroup_iter+0x366/0x480 [ 189.772427] balance_pgdat+0x563/0xb00 [ 189.772428] ? balance_pgdat+0x563/0xb00 [ 189.772430] ? trace_hardirqs_on+0x1e/0xe0 [ 189.772431] ? finish_task_switch.isra.0+0xcb/0x330 [ 189.772433] ? __switch_to_asm+0x33/0x70 [ 189.772437] kswapd+0x1e8/0x430 [ 189.772438] ? __pfx_autoremove_wake_function+0x10/0x10 [ 189.772440] ? __pfx_kswapd+0x10/0x10 [ 189.772441] kthread+0x10b/0x260 [ 189.772443] ? __pfx_kthread+0x10/0x10 [ 189.772444] ret_from_fork+0x44/0x70 [ 189.772446] ? __pfx_kthread+0x10/0x10 [ 189.772447] ret_from_fork_asm+0x1a/0x30 [ 189.772450] </TASK> [2]: [ 8.760253] ====================================================== [ 8.760254] WARNING: possible circular locking dependency detected [ 8.760255] 6.14.0-rc6-xe+ #7 Tainted: G U [ 8.760256] ------------------------------------------------------ [ 8.760257] (udev-worker)/674 is trying to acquire lock: [ 8.760259] ffff888100e39148 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_remove+0x32/0x60 [ 8.760265] but task is already holding lock: [ 8.760266] ffff888110dc7680 (&q->q_usage_counter(io)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30 [ 8.760272] which lock already depends on the new lock. [ 8.760272] the existing dependency chain (in reverse order) is: [ 8.760273] -> #2 (&q->q_usage_counter(io)#27){++++}-{0:0}: [ 8.760276] blk_alloc_queue+0x30a/0x350 [ 8.760279] blk_mq_alloc_queue+0x6b/0xe0 [ 8.760281] scsi_alloc_sdev+0x276/0x3c0 [ 8.760284] scsi_probe_and_add_lun+0x22a/0x440 [ 8.760286] __scsi_scan_target+0x109/0x230 [ 8.760288] scsi_scan_channel+0x65/0xc0 [ 8.760290] scsi_scan_host_selected+0xff/0x140 [ 8.760292] do_scsi_scan_host+0xa7/0xc0 [ 8.760293] do_scan_async+0x1c/0x160 [ 8.760295] async_run_entry_fn+0x32/0x150 [ 8.760299] process_one_work+0x224/0x5f0 [ 8.760302] worker_thread+0x1d4/0x3e0 [ 8.760304] kthread+0x10b/0x260 [ 8.760306] ret_from_fork+0x44/0x70 [ 8.760309] ret_from_fork_asm+0x1a/0x30 [ 8.760312] -> #1 (fs_reclaim){+.+.}-{0:0}: [ 8.760315] fs_reclaim_acquire+0xc5/0x100 [ 8.760317] kmem_cache_alloc_lru_noprof+0x4a/0x480 [ 8.760319] alloc_inode+0xaa/0xe0 [ 8.760322] iget_locked+0x157/0x330 [ 8.760323] kernfs_get_inode+0x1b/0x110 [ 8.760325] kernfs_get_tree+0x1b0/0x2e0 [ 8.760327] sysfs_get_tree+0x1f/0x60 [ 8.760329] vfs_get_tree+0x2a/0xf0 [ 8.760332] path_mount+0x4cd/0xc00 [ 8.760334] __x64_sys_mount+0x119/0x150 [ 8.760336] x64_sys_call+0x14f2/0x2310 [ 8.760338] do_syscall_64+0x91/0x180 [ 8.760340] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 8.760342] -> #0 (&root->kernfs_rwsem){++++}-{3:3}: [ 8.760345] __lock_acquire+0x1525/0x2760 [ 8.760347] lock_acquire+0xca/0x310 [ 8.760348] down_write+0x3e/0xf0 [ 8.760350] kernfs_remove+0x32/0x60 [ 8.760351] sysfs_remove_dir+0x4f/0x60 [ 8.760353] __kobject_del+0x33/0xa0 [ 8.760355] kobject_del+0x13/0x30 [ 8.760356] elv_unregister_queue+0x52/0x80 [ 8.760358] elevator_switch+0x68/0x360 [ 8.760360] elv_iosched_store+0x14b/0x1b0 [ 8.760362] queue_attr_store+0x181/0x1e0 [ 8.760364] sysfs_kf_write+0x49/0x80 [ 8.760366] kernfs_fop_write_iter+0x17d/0x250 [ 8.760367] vfs_write+0x281/0x540 [ 8.760370] ksys_write+0x72/0xf0 [ 8.760372] __x64_sys_write+0x19/0x30 [ 8.760374] x64_sys_call+0x2a3/0x2310 [ 8.760376] do_syscall_64+0x91/0x180 [ 8.760377] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 8.760380] other info that might help us debug this: [ 8.760380] Chain exists of: &root->kernfs_rwsem --> fs_reclaim --> &q->q_usage_counter(io)#27 [ 8.760384] Possible unsafe locking scenario: [ 8.760384] CPU0 CPU1 [ 8.760385] ---- ---- [ 8.760385] lock(&q->q_usage_counter(io)#27); [ 8.760387] lock(fs_reclaim); [ 8.760388] lock(&q->q_usage_counter(io)#27); [ 8.760390] lock(&root->kernfs_rwsem); [ 8.760391] *** DEADLOCK *** [ 8.760391] 6 locks held by (udev-worker)/674: [ 8.760392] #0: ffff8881209ac420 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0x72/0xf0 [ 8.760398] #1: ffff88810c80f488 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x136/0x250 [ 8.760402] #2: ffff888125d1d330 (kn->active#101){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x13f/0x250 [ 8.760406] #3: ffff888110dc7bb0 (&q->sysfs_lock){+.+.}-{3:3}, at: queue_attr_store+0x148/0x1e0 [ 8.760411] #4: ffff888110dc7680 (&q->q_usage_counter(io)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30 [ 8.760416] #5: ffff888110dc76b8 (&q->q_usage_counter(queue)#27){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x12/0x30 [ 8.760421] stack backtrace: [ 8.760422] CPU: 7 UID: 0 PID: 674 Comm: (udev-worker) Tainted: G U 6.14.0-rc6-xe+ #7 [ 8.760424] Tainted: [U]=USER [ 8.760425] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023 [ 8.760426] Call Trace: [ 8.760427] <TASK> [ 8.760428] dump_stack_lvl+0x6e/0xa0 [ 8.760431] dump_stack+0x10/0x18 [ 8.760433] print_circular_bug.cold+0x17a/0x1b7 [ 8.760437] check_noncircular+0x13a/0x150 [ 8.760441] ? save_trace+0x54/0x360 [ 8.760445] __lock_acquire+0x1525/0x2760 [ 8.760446] ? irqentry_exit+0x3a/0xb0 [ 8.760448] ? sysvec_apic_timer_interrupt+0x57/0xc0 [ 8.760452] lock_acquire+0xca/0x310 [ 8.760453] ? kernfs_remove+0x32/0x60 [ 8.760457] down_write+0x3e/0xf0 [ 8.760459] ? kernfs_remove+0x32/0x60 [ 8.760460] kernfs_remove+0x32/0x60 [ 8.760462] sysfs_remove_dir+0x4f/0x60 [ 8.760464] __kobject_del+0x33/0xa0 [ 8.760466] kobject_del+0x13/0x30 [ 8.760467] elv_unregister_queue+0x52/0x80 [ 8.760470] elevator_switch+0x68/0x360 [ 8.760472] elv_iosched_store+0x14b/0x1b0 [ 8.760475] queue_attr_store+0x181/0x1e0 [ 8.760479] ? lock_acquire+0xca/0x310 [ 8.760480] ? kernfs_fop_write_iter+0x13f/0x250 [ 8.760482] ? lock_is_held_type+0xa3/0x130 [ 8.760485] sysfs_kf_write+0x49/0x80 [ 8.760487] kernfs_fop_write_iter+0x17d/0x250 [ 8.760489] vfs_write+0x281/0x540 [ 8.760494] ksys_write+0x72/0xf0 [ 8.760497] __x64_sys_write+0x19/0x30 [ 8.760499] x64_sys_call+0x2a3/0x2310 [ 8.760502] do_syscall_64+0x91/0x180 [ 8.760504] ? trace_hardirqs_off+0x5d/0xe0 [ 8.760506] ? handle_softirqs+0x479/0x4d0 [ 8.760508] ? hrtimer_interrupt+0x13f/0x280 [ 8.760511] ? irqentry_exit_to_user_mode+0x8b/0x260 [ 8.760513] ? clear_bhb_loop+0x15/0x70 [ 8.760515] ? clear_bhb_loop+0x15/0x70 [ 8.760516] ? clear_bhb_loop+0x15/0x70 [ 8.760518] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 8.760520] RIP: 0033:0x7aa3bf2f5504 [ 8.760522] Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d c5 8b 10 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 [ 8.760523] RSP: 002b:00007ffc1e3697d8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 [ 8.760526] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007aa3bf2f5504 [ 8.760527] RDX: 0000000000000003 RSI: 00007ffc1e369ae0 RDI: 000000000000001c [ 8.760528] RBP: 00007ffc1e369800 R08: 00007aa3bf3f51c8 R09: 00007ffc1e3698b0 [ 8.760528] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 [ 8.760529] R13: 00007ffc1e369ae0 R14: 0000613ccf21f2f0 R15: 00007aa3bf3f4e80 [ 8.760533] </TASK> v2: - Update a code comment to increase readability (Ming Lei). Cc: Jens Axboe <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Ming Lei <[email protected]> Signed-off-by: Thomas Hellström <[email protected]> Reviewed-by: Ming Lei <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Ming Lei <[email protected]>
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Oct 24, 2025
JIRA: https://issues.redhat.com/browse/RHEL-112997 commit 9730763 Author: Nilay Shroff <[email protected]> Date: Wed Mar 19 16:23:46 2025 +0530 block: correct locking order for protecting blk-wbt parameters The commit '245618f8e45f ("block: protect wbt_lat_usec using q-> elevator_lock")' introduced q->elevator_lock to protect updates to blk-wbt parameters when writing to the sysfs attribute wbt_ lat_usec and the cgroup attribute io.cost.qos. However, both these attributes also acquire q->rq_qos_mutex, leading to the following lockdep warning: ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc5+ #138 Not tainted ------------------------------------------------------ bash/5902 is trying to acquire lock: c000000085d495a0 (&q->rq_qos_mutex){+.+.}-{4:4}, at: wbt_init+0x164/0x238 but task is already holding lock: c000000085d498c8 (&q->elevator_lock){+.+.}-{4:4}, at: queue_wb_lat_store+0xb0/0x20c which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&q->elevator_lock){+.+.}-{4:4}: __mutex_lock+0xf0/0xa58 ioc_qos_write+0x16c/0x85c cgroup_file_write+0xc4/0x32c kernfs_fop_write_iter+0x1b8/0x29c vfs_write+0x410/0x584 ksys_write+0x84/0x140 system_call_exception+0x134/0x360 system_call_vectored_common+0x15c/0x2ec -> #0 (&q->rq_qos_mutex){+.+.}-{4:4}: __lock_acquire+0x1b6c/0x2ae0 lock_acquire+0x140/0x430 __mutex_lock+0xf0/0xa58 wbt_init+0x164/0x238 queue_wb_lat_store+0x1dc/0x20c queue_attr_store+0x12c/0x164 sysfs_kf_write+0x6c/0xb0 kernfs_fop_write_iter+0x1b8/0x29c vfs_write+0x410/0x584 ksys_write+0x84/0x140 system_call_exception+0x134/0x360 system_call_vectored_common+0x15c/0x2ec other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&q->elevator_lock); lock(&q->rq_qos_mutex); lock(&q->elevator_lock); lock(&q->rq_qos_mutex); *** DEADLOCK *** 6 locks held by bash/5902: #0: c000000051122400 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x84/0x140 #1: c00000007383f088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x174/0x29c #2: c000000008550428 (kn->active#182){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x180/0x29c #3: c000000085d493a8 (&q->q_usage_counter(io)#5){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x28/0x40 #4: c000000085d493e0 (&q->q_usage_counter(queue)#5){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x28/0x40 #5: c000000085d498c8 (&q->elevator_lock){+.+.}-{4:4}, at: queue_wb_lat_store+0xb0/0x20c stack backtrace: CPU: 17 UID: 0 PID: 5902 Comm: bash Kdump: loaded Not tainted 6.14.0-rc5+ #138 Hardware name: IBM,9043-MRX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_028) hv:phyp pSeries Call Trace: [c0000000721ef590] [c00000000118f8a8] dump_stack_lvl+0x108/0x18c (unreliable) [c0000000721ef5c0] [c00000000022563c] print_circular_bug+0x448/0x604 [c0000000721ef670] [c000000000225a44] check_noncircular+0x24c/0x26c [c0000000721ef740] [c00000000022bf28] __lock_acquire+0x1b6c/0x2ae0 [c0000000721ef870] [c000000000229240] lock_acquire+0x140/0x430 [c0000000721ef970] [c0000000011cfbec] __mutex_lock+0xf0/0xa58 [c0000000721efaa0] [c00000000096c46c] wbt_init+0x164/0x238 [c0000000721efaf0] [c0000000008f8cd8] queue_wb_lat_store+0x1dc/0x20c [c0000000721efb50] [c0000000008f8fa0] queue_attr_store+0x12c/0x164 [c0000000721efc60] [c0000000007c11cc] sysfs_kf_write+0x6c/0xb0 [c0000000721efca0] [c0000000007bfa4c] kernfs_fop_write_iter+0x1b8/0x29c [c0000000721efcf0] [c0000000006a281c] vfs_write+0x410/0x584 [c0000000721efdc0] [c0000000006a2cc8] ksys_write+0x84/0x140 [c0000000721efe10] [c000000000031b64] system_call_exception+0x134/0x360 [c0000000721efe50] [c00000000000cedc] system_call_vectored_common+0x15c/0x2ec >From the above log it's apparent that method which writes to sysfs attr wbt_lat_usec acquires q->elevator_lock first, and then acquires q->rq_ qos_mutex. However the another method which writes to io.cost.qos, acquires q->rq_qos_mutex first, and then acquires q->rq_qos_mutex. So this could potentially cause the deadlock. A closer look at ioc_qos_write shows that correcting the lock order is non-trivial because q->rq_qos_mutex is acquired in blkg_conf_open_bdev and released in blkg_conf_exit. The function blkg_conf_open_bdev is responsible for parsing user input and finding the corresponding block device (bdev) from the user provided major:minor number. Since we do not know the bdev until blkg_conf_open_bdev completes, we cannot simply move q->elevator_lock acquisition before blkg_conf_open_ bdev. So to address this, we intoduce new helpers blkg_conf_open_bdev_ frozen and blkg_conf_exit_frozen which are just wrappers around blkg_ conf_open_bdev and blkg_conf_exit respectively. The helper blkg_conf_ open_bdev_frozen is similar to blkg_conf_open_bdev, but additionally freezes the queue, acquires q->elevator_lock and ensures the correct locking order is followed between q->elevator_lock and q->rq_qos_mutex. Similarly another helper blkg_conf_exit_frozen in addition to unfreezing the queue ensures that we release the locks in correct order. By using these helpers, now we maintain the same locking order in all code paths where we update blk-wbt parameters. Fixes: 245618f ("block: protect wbt_lat_usec using q->elevator_lock") Reported-by: kernel test robot <[email protected]> Closes: https://lore.kernel.org/oe-lkp/[email protected] Signed-off-by: Nilay Shroff <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Ming Lei <[email protected]>
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…xit() JIRA: https://issues.redhat.com/browse/RHEL-112997 commit 78c2713 Author: Ming Lei <[email protected]> Date: Mon May 5 22:18:03 2025 +0800 block: move wbt_enable_default() out of queue freezing from sched ->exit() scheduler's ->exit() is called with queue frozen and elevator lock is held, and wbt_enable_default() can't be called with queue frozen, otherwise the following lockdep warning is triggered: #6 (&q->rq_qos_mutex){+.+.}-{4:4}: #5 (&eq->sysfs_lock){+.+.}-{4:4}: #4 (&q->elevator_lock){+.+.}-{4:4}: #3 (&q->q_usage_counter(io)#3){++++}-{0:0}: #2 (fs_reclaim){+.+.}-{0:0}: #1 (&sb->s_type->i_mutex_key#3){+.+.}-{4:4}: #0 (&q->debugfs_mutex){+.+.}-{4:4}: Fix the issue by moving wbt_enable_default() out of bfq's exit(), and call it from elevator_change_done(). Meantime add disk->rqos_state_mutex for covering wbt state change, which matches the purpose more than ->elevator_lock. Reviewed-by: Hannes Reinecke <[email protected]> Reviewed-by: Nilay Shroff <[email protected]> Signed-off-by: Ming Lei <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Ming Lei <[email protected]>
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The original code causes a circular locking dependency found by lockdep. ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 Tainted: G S U ------------------------------------------------------ xe_fault_inject/5091 is trying to acquire lock: ffff888156815688 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}, at: __flush_work+0x25d/0x660 but task is already holding lock: ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&devcd->mutex){+.+.}-{3:3}: mutex_lock_nested+0x4e/0xc0 devcd_data_write+0x27/0x90 sysfs_kf_bin_write+0x80/0xf0 kernfs_fop_write_iter+0x169/0x220 vfs_write+0x293/0x560 ksys_write+0x72/0xf0 __x64_sys_write+0x19/0x30 x64_sys_call+0x2bf/0x2660 do_syscall_64+0x93/0xb60 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (kn->active#236){++++}-{0:0}: kernfs_drain+0x1e2/0x200 __kernfs_remove+0xae/0x400 kernfs_remove_by_name_ns+0x5d/0xc0 remove_files+0x54/0x70 sysfs_remove_group+0x3d/0xa0 sysfs_remove_groups+0x2e/0x60 device_remove_attrs+0xc7/0x100 device_del+0x15d/0x3b0 devcd_del+0x19/0x30 process_one_work+0x22b/0x6f0 worker_thread+0x1e8/0x3d0 kthread+0x11c/0x250 ret_from_fork+0x26c/0x2e0 ret_from_fork_asm+0x1a/0x30 -> #0 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}: __lock_acquire+0x1661/0x2860 lock_acquire+0xc4/0x2f0 __flush_work+0x27a/0x660 flush_delayed_work+0x5d/0xa0 dev_coredump_put+0x63/0xa0 xe_driver_devcoredump_fini+0x12/0x20 [xe] devm_action_release+0x12/0x30 release_nodes+0x3a/0x120 devres_release_all+0x8a/0xd0 device_unbind_cleanup+0x12/0x80 device_release_driver_internal+0x23a/0x280 device_driver_detach+0x14/0x20 unbind_store+0xaf/0xc0 drv_attr_store+0x21/0x50 sysfs_kf_write+0x4a/0x80 kernfs_fop_write_iter+0x169/0x220 vfs_write+0x293/0x560 ksys_write+0x72/0xf0 __x64_sys_write+0x19/0x30 x64_sys_call+0x2bf/0x2660 do_syscall_64+0x93/0xb60 entry_SYSCALL_64_after_hwframe+0x76/0x7e other info that might help us debug this: Chain exists of: (work_completion)(&(&devcd->del_wk)->work) --> kn->active#236 --> &devcd->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&devcd->mutex); lock(kn->active#236); lock(&devcd->mutex); lock((work_completion)(&(&devcd->del_wk)->work)); *** DEADLOCK *** 5 locks held by xe_fault_inject/5091: #0: ffff8881129f9488 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x72/0xf0 #1: ffff88810c755078 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x123/0x220 #2: ffff8881054811a0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x55/0x280 #3: ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0 #4: ffffffff8359e020 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x72/0x660 stack backtrace: CPU: 14 UID: 0 PID: 5091 Comm: xe_fault_inject Tainted: G S U 6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 PREEMPT_{RT,(lazy)} Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER Hardware name: Micro-Star International Co., Ltd. MS-7D25/PRO Z690-A DDR4(MS-7D25), BIOS 1.10 12/13/2021 Call Trace: <TASK> dump_stack_lvl+0x91/0xf0 dump_stack+0x10/0x20 print_circular_bug+0x285/0x360 check_noncircular+0x135/0x150 ? register_lock_class+0x48/0x4a0 __lock_acquire+0x1661/0x2860 lock_acquire+0xc4/0x2f0 ? __flush_work+0x25d/0x660 ? mark_held_locks+0x46/0x90 ? __flush_work+0x25d/0x660 __flush_work+0x27a/0x660 ? __flush_work+0x25d/0x660 ? trace_hardirqs_on+0x1e/0xd0 ? __pfx_wq_barrier_func+0x10/0x10 flush_delayed_work+0x5d/0xa0 dev_coredump_put+0x63/0xa0 xe_driver_devcoredump_fini+0x12/0x20 [xe] devm_action_release+0x12/0x30 release_nodes+0x3a/0x120 devres_release_all+0x8a/0xd0 device_unbind_cleanup+0x12/0x80 device_release_driver_internal+0x23a/0x280 ? bus_find_device+0xa8/0xe0 device_driver_detach+0x14/0x20 unbind_store+0xaf/0xc0 drv_attr_store+0x21/0x50 sysfs_kf_write+0x4a/0x80 kernfs_fop_write_iter+0x169/0x220 vfs_write+0x293/0x560 ksys_write+0x72/0xf0 __x64_sys_write+0x19/0x30 x64_sys_call+0x2bf/0x2660 do_syscall_64+0x93/0xb60 ? __f_unlock_pos+0x15/0x20 ? __x64_sys_getdents64+0x9b/0x130 ? __pfx_filldir64+0x10/0x10 ? do_syscall_64+0x1a2/0xb60 ? clear_bhb_loop+0x30/0x80 ? clear_bhb_loop+0x30/0x80 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x76e292edd574 Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 RSP: 002b:00007fffe247a828 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000076e292edd574 RDX: 000000000000000c RSI: 00006267f6306063 RDI: 000000000000000b RBP: 000000000000000c R08: 000076e292fc4b20 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00006267f6306063 R13: 000000000000000b R14: 00006267e6859c00 R15: 000076e29322a000 </TASK> xe 0000:03:00.0: [drm] Xe device coredump has been deleted. Fixes: 01daccf ("devcoredump : Serialize devcd_del work") Cc: Mukesh Ojha <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Rafael J. Wysocki <[email protected]> Cc: Danilo Krummrich <[email protected]> Cc: [email protected] Cc: [email protected] # v6.1+ Signed-off-by: Maarten Lankhorst <[email protected]> Cc: Matthew Brost <[email protected]> Acked-by: Mukesh Ojha <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
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JIRA: https://issues.redhat.com/browse/RHEL-115591 Upstream Status: linux.git Conflicts: * (context) Missing upstream commit 5cde39e ("vxlan: Rename FDB Txlookup function"): The vxlan_find_mac_tx() function is still called "vxlan_find_mac" in Centos Stream 10. commit 1f5d2fd Author: Ido Schimmel <[email protected]> Date: Mon Sep 1 09:50:34 2025 +0300 vxlan: Fix NPD in {arp,neigh}_reduce() when using nexthop objects When the "proxy" option is enabled on a VXLAN device, the device will suppress ARP requests and IPv6 Neighbor Solicitation messages if it is able to reply on behalf of the remote host. That is, if a matching and valid neighbor entry is configured on the VXLAN device whose MAC address is not behind the "any" remote (0.0.0.0 / ::). The code currently assumes that the FDB entry for the neighbor's MAC address points to a valid remote destination, but this is incorrect if the entry is associated with an FDB nexthop group. This can result in a NPD [1][3] which can be reproduced using [2][4]. Fix by checking that the remote destination exists before dereferencing it. [1] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] CPU: 4 UID: 0 PID: 365 Comm: arping Not tainted 6.17.0-rc2-virtme-g2a89cb21162c #2 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014 RIP: 0010:vxlan_xmit+0xb58/0x15f0 [...] Call Trace: <TASK> dev_hard_start_xmit+0x5d/0x1c0 __dev_queue_xmit+0x246/0xfd0 packet_sendmsg+0x113a/0x1850 __sock_sendmsg+0x38/0x70 __sys_sendto+0x126/0x180 __x64_sys_sendto+0x24/0x30 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [2] #!/bin/bash ip address add 192.0.2.1/32 dev lo ip nexthop add id 1 via 192.0.2.2 fdb ip nexthop add id 10 group 1 fdb ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 4789 proxy ip neigh add 192.0.2.3 lladdr 00:11:22:33:44:55 nud perm dev vx0 bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10 arping -b -c 1 -s 192.0.2.1 -I vx0 192.0.2.3 [3] BUG: kernel NULL pointer dereference, address: 0000000000000000 [...] CPU: 13 UID: 0 PID: 372 Comm: ndisc6 Not tainted 6.17.0-rc2-virtmne-g6ee90cb26014 #3 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1v996), BIOS 1.17.0-4.fc41 04/01/2x014 RIP: 0010:vxlan_xmit+0x803/0x1600 [...] Call Trace: <TASK> dev_hard_start_xmit+0x5d/0x1c0 __dev_queue_xmit+0x246/0xfd0 ip6_finish_output2+0x210/0x6c0 ip6_finish_output+0x1af/0x2b0 ip6_mr_output+0x92/0x3e0 ip6_send_skb+0x30/0x90 rawv6_sendmsg+0xe6e/0x12e0 __sock_sendmsg+0x38/0x70 __sys_sendto+0x126/0x180 __x64_sys_sendto+0x24/0x30 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f383422ec77 [4] #!/bin/bash ip address add 2001:db8:1::1/128 dev lo ip nexthop add id 1 via 2001:db8:1::1 fdb ip nexthop add id 10 group 1 fdb ip link add name vx0 up type vxlan id 10010 local 2001:db8:1::1 dstport 4789 proxy ip neigh add 2001:db8:1::3 lladdr 00:11:22:33:44:55 nud perm dev vx0 bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10 ndisc6 -r 1 -s 2001:db8:1::1 -w 1 2001:db8:1::3 vx0 Fixes: 1274e1c ("vxlan: ecmp support for mac fdb entries") Reviewed-by: Petr Machata <[email protected]> Signed-off-by: Ido Schimmel <[email protected]> Reviewed-by: Nikolay Aleksandrov <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]> Signed-off-by: Guillaume Nault <[email protected]>
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Oct 30, 2025
JIRA: https://issues.redhat.com/browse/RHEL-115358 commit c98cc97 Author: Steven Rostedt <[email protected]> Date: Tue May 27 10:58:20 2025 -0400 ring-buffer: Move cpus_read_lock() outside of buffer->mutex Running a modified trace-cmd record --nosplice where it does a mmap of the ring buffer when '--nosplice' is set, caused the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc7-test-00002-gfb7d03d8a82f #551 Not tainted ------------------------------------------------------ trace-cmd/1113 is trying to acquire lock: ffff888100062888 (&buffer->mutex){+.+.}-{4:4}, at: ring_buffer_map+0x11c/0xe70 but task is already holding lock: ffff888100a5f9f8 (&cpu_buffer->mapping_lock){+.+.}-{4:4}, at: ring_buffer_map+0xcf/0xe70 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&cpu_buffer->mapping_lock){+.+.}-{4:4}: __mutex_lock+0x192/0x18c0 ring_buffer_map+0xcf/0xe70 tracing_buffers_mmap+0x1c4/0x3b0 __mmap_region+0xd8d/0x1f70 do_mmap+0x9d7/0x1010 vm_mmap_pgoff+0x20b/0x390 ksys_mmap_pgoff+0x2e9/0x440 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #4 (&mm->mmap_lock){++++}-{4:4}: __might_fault+0xa5/0x110 _copy_to_user+0x22/0x80 _perf_ioctl+0x61b/0x1b70 perf_ioctl+0x62/0x90 __x64_sys_ioctl+0x134/0x190 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #3 (&cpuctx_mutex){+.+.}-{4:4}: __mutex_lock+0x192/0x18c0 perf_event_init_cpu+0x325/0x7c0 perf_event_init+0x52a/0x5b0 start_kernel+0x263/0x3e0 x86_64_start_reservations+0x24/0x30 x86_64_start_kernel+0x95/0xa0 common_startup_64+0x13e/0x141 -> #2 (pmus_lock){+.+.}-{4:4}: __mutex_lock+0x192/0x18c0 perf_event_init_cpu+0xb7/0x7c0 cpuhp_invoke_callback+0x2c0/0x1030 __cpuhp_invoke_callback_range+0xbf/0x1f0 _cpu_up+0x2e7/0x690 cpu_up+0x117/0x170 cpuhp_bringup_mask+0xd5/0x120 bringup_nonboot_cpus+0x13d/0x170 smp_init+0x2b/0xf0 kernel_init_freeable+0x441/0x6d0 kernel_init+0x1e/0x160 ret_from_fork+0x34/0x70 ret_from_fork_asm+0x1a/0x30 -> #1 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x2a/0xd0 ring_buffer_resize+0x610/0x14e0 __tracing_resize_ring_buffer.part.0+0x42/0x120 tracing_set_tracer+0x7bd/0xa80 tracing_set_trace_write+0x132/0x1e0 vfs_write+0x21c/0xe80 ksys_write+0xf9/0x1c0 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&buffer->mutex){+.+.}-{4:4}: __lock_acquire+0x1405/0x2210 lock_acquire+0x174/0x310 __mutex_lock+0x192/0x18c0 ring_buffer_map+0x11c/0xe70 tracing_buffers_mmap+0x1c4/0x3b0 __mmap_region+0xd8d/0x1f70 do_mmap+0x9d7/0x1010 vm_mmap_pgoff+0x20b/0x390 ksys_mmap_pgoff+0x2e9/0x440 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e other info that might help us debug this: Chain exists of: &buffer->mutex --> &mm->mmap_lock --> &cpu_buffer->mapping_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpu_buffer->mapping_lock); lock(&mm->mmap_lock); lock(&cpu_buffer->mapping_lock); lock(&buffer->mutex); *** DEADLOCK *** 2 locks held by trace-cmd/1113: #0: ffff888106b847e0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x192/0x390 #1: ffff888100a5f9f8 (&cpu_buffer->mapping_lock){+.+.}-{4:4}, at: ring_buffer_map+0xcf/0xe70 stack backtrace: CPU: 5 UID: 0 PID: 1113 Comm: trace-cmd Not tainted 6.15.0-rc7-test-00002-gfb7d03d8a82f #551 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x6e/0xa0 print_circular_bug.cold+0x178/0x1be check_noncircular+0x146/0x160 __lock_acquire+0x1405/0x2210 lock_acquire+0x174/0x310 ? ring_buffer_map+0x11c/0xe70 ? ring_buffer_map+0x11c/0xe70 ? __mutex_lock+0x169/0x18c0 __mutex_lock+0x192/0x18c0 ? ring_buffer_map+0x11c/0xe70 ? ring_buffer_map+0x11c/0xe70 ? function_trace_call+0x296/0x370 ? __pfx___mutex_lock+0x10/0x10 ? __pfx_function_trace_call+0x10/0x10 ? __pfx___mutex_lock+0x10/0x10 ? _raw_spin_unlock+0x2d/0x50 ? ring_buffer_map+0x11c/0xe70 ? ring_buffer_map+0x11c/0xe70 ? __mutex_lock+0x5/0x18c0 ring_buffer_map+0x11c/0xe70 ? do_raw_spin_lock+0x12d/0x270 ? find_held_lock+0x2b/0x80 ? _raw_spin_unlock+0x2d/0x50 ? rcu_is_watching+0x15/0xb0 ? _raw_spin_unlock+0x2d/0x50 ? trace_preempt_on+0xd0/0x110 tracing_buffers_mmap+0x1c4/0x3b0 __mmap_region+0xd8d/0x1f70 ? ring_buffer_lock_reserve+0x99/0xff0 ? __pfx___mmap_region+0x10/0x10 ? ring_buffer_lock_reserve+0x99/0xff0 ? __pfx_ring_buffer_lock_reserve+0x10/0x10 ? __pfx_ring_buffer_lock_reserve+0x10/0x10 ? bpf_lsm_mmap_addr+0x4/0x10 ? security_mmap_addr+0x46/0xd0 ? lock_is_held_type+0xd9/0x130 do_mmap+0x9d7/0x1010 ? 0xffffffffc0370095 ? __pfx_do_mmap+0x10/0x10 vm_mmap_pgoff+0x20b/0x390 ? __pfx_vm_mmap_pgoff+0x10/0x10 ? 0xffffffffc0370095 ksys_mmap_pgoff+0x2e9/0x440 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fb0963a7de2 Code: 00 00 00 0f 1f 44 00 00 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 3b 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 5b 5d c3 0f 1f 00 48 8b 05 e1 9f 0d 00 64 RSP: 002b:00007ffdcc8fb878 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb0963a7de2 RDX: 0000000000000001 RSI: 0000000000001000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdcc8fbe68 R14: 00007fb096628000 R15: 00005633e01a5c90 </TASK> The issue is that cpus_read_lock() is taken within buffer->mutex. The memory mapped pages are taken with the mmap_lock held. The buffer->mutex is taken within the cpu_buffer->mapping_lock. There's quite a chain with all these locks, where the deadlock can be fixed by moving the cpus_read_lock() outside the taking of the buffer->mutex. Cc: [email protected] Cc: Masami Hiramatsu <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Vincent Donnefort <[email protected]> Link: https://lore.kernel.org/[email protected] Fixes: 117c392 ("ring-buffer: Introducing ring-buffer mapping functions") Signed-off-by: Steven Rostedt (Google) <[email protected]> Signed-off-by: Jerome Marchand <[email protected]>
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[ Upstream commit a91c809 ] The original code causes a circular locking dependency found by lockdep. ====================================================== WARNING: possible circular locking dependency detected 6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 Tainted: G S U ------------------------------------------------------ xe_fault_inject/5091 is trying to acquire lock: ffff888156815688 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}, at: __flush_work+0x25d/0x660 but task is already holding lock: ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&devcd->mutex){+.+.}-{3:3}: mutex_lock_nested+0x4e/0xc0 devcd_data_write+0x27/0x90 sysfs_kf_bin_write+0x80/0xf0 kernfs_fop_write_iter+0x169/0x220 vfs_write+0x293/0x560 ksys_write+0x72/0xf0 __x64_sys_write+0x19/0x30 x64_sys_call+0x2bf/0x2660 do_syscall_64+0x93/0xb60 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #1 (kn->active#236){++++}-{0:0}: kernfs_drain+0x1e2/0x200 __kernfs_remove+0xae/0x400 kernfs_remove_by_name_ns+0x5d/0xc0 remove_files+0x54/0x70 sysfs_remove_group+0x3d/0xa0 sysfs_remove_groups+0x2e/0x60 device_remove_attrs+0xc7/0x100 device_del+0x15d/0x3b0 devcd_del+0x19/0x30 process_one_work+0x22b/0x6f0 worker_thread+0x1e8/0x3d0 kthread+0x11c/0x250 ret_from_fork+0x26c/0x2e0 ret_from_fork_asm+0x1a/0x30 -> #0 ((work_completion)(&(&devcd->del_wk)->work)){+.+.}-{0:0}: __lock_acquire+0x1661/0x2860 lock_acquire+0xc4/0x2f0 __flush_work+0x27a/0x660 flush_delayed_work+0x5d/0xa0 dev_coredump_put+0x63/0xa0 xe_driver_devcoredump_fini+0x12/0x20 [xe] devm_action_release+0x12/0x30 release_nodes+0x3a/0x120 devres_release_all+0x8a/0xd0 device_unbind_cleanup+0x12/0x80 device_release_driver_internal+0x23a/0x280 device_driver_detach+0x14/0x20 unbind_store+0xaf/0xc0 drv_attr_store+0x21/0x50 sysfs_kf_write+0x4a/0x80 kernfs_fop_write_iter+0x169/0x220 vfs_write+0x293/0x560 ksys_write+0x72/0xf0 __x64_sys_write+0x19/0x30 x64_sys_call+0x2bf/0x2660 do_syscall_64+0x93/0xb60 entry_SYSCALL_64_after_hwframe+0x76/0x7e other info that might help us debug this: Chain exists of: (work_completion)(&(&devcd->del_wk)->work) --> kn->active#236 --> &devcd->mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&devcd->mutex); lock(kn->active#236); lock(&devcd->mutex); lock((work_completion)(&(&devcd->del_wk)->work)); *** DEADLOCK *** 5 locks held by xe_fault_inject/5091: #0: ffff8881129f9488 (sb_writers#5){.+.+}-{0:0}, at: ksys_write+0x72/0xf0 #1: ffff88810c755078 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x123/0x220 #2: ffff8881054811a0 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x55/0x280 #3: ffff888156815620 (&devcd->mutex){+.+.}-{3:3}, at: dev_coredump_put+0x3f/0xa0 #4: ffffffff8359e020 (rcu_read_lock){....}-{1:2}, at: __flush_work+0x72/0x660 stack backtrace: CPU: 14 UID: 0 PID: 5091 Comm: xe_fault_inject Tainted: G S U 6.16.0-rc6-lgci-xe-xe-pw-151626v3+ #1 PREEMPT_{RT,(lazy)} Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER Hardware name: Micro-Star International Co., Ltd. MS-7D25/PRO Z690-A DDR4(MS-7D25), BIOS 1.10 12/13/2021 Call Trace: <TASK> dump_stack_lvl+0x91/0xf0 dump_stack+0x10/0x20 print_circular_bug+0x285/0x360 check_noncircular+0x135/0x150 ? register_lock_class+0x48/0x4a0 __lock_acquire+0x1661/0x2860 lock_acquire+0xc4/0x2f0 ? __flush_work+0x25d/0x660 ? mark_held_locks+0x46/0x90 ? __flush_work+0x25d/0x660 __flush_work+0x27a/0x660 ? __flush_work+0x25d/0x660 ? trace_hardirqs_on+0x1e/0xd0 ? __pfx_wq_barrier_func+0x10/0x10 flush_delayed_work+0x5d/0xa0 dev_coredump_put+0x63/0xa0 xe_driver_devcoredump_fini+0x12/0x20 [xe] devm_action_release+0x12/0x30 release_nodes+0x3a/0x120 devres_release_all+0x8a/0xd0 device_unbind_cleanup+0x12/0x80 device_release_driver_internal+0x23a/0x280 ? bus_find_device+0xa8/0xe0 device_driver_detach+0x14/0x20 unbind_store+0xaf/0xc0 drv_attr_store+0x21/0x50 sysfs_kf_write+0x4a/0x80 kernfs_fop_write_iter+0x169/0x220 vfs_write+0x293/0x560 ksys_write+0x72/0xf0 __x64_sys_write+0x19/0x30 x64_sys_call+0x2bf/0x2660 do_syscall_64+0x93/0xb60 ? __f_unlock_pos+0x15/0x20 ? __x64_sys_getdents64+0x9b/0x130 ? __pfx_filldir64+0x10/0x10 ? do_syscall_64+0x1a2/0xb60 ? clear_bhb_loop+0x30/0x80 ? clear_bhb_loop+0x30/0x80 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x76e292edd574 Code: c7 00 16 00 00 00 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 80 3d d5 ea 0e 00 00 74 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 55 48 89 e5 48 83 ec 20 48 89 RSP: 002b:00007fffe247a828 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000076e292edd574 RDX: 000000000000000c RSI: 00006267f6306063 RDI: 000000000000000b RBP: 000000000000000c R08: 000076e292fc4b20 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00006267f6306063 R13: 000000000000000b R14: 00006267e6859c00 R15: 000076e29322a000 </TASK> xe 0000:03:00.0: [drm] Xe device coredump has been deleted. Fixes: 01daccf ("devcoredump : Serialize devcd_del work") Cc: Mukesh Ojha <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: Johannes Berg <[email protected]> Cc: Rafael J. Wysocki <[email protected]> Cc: Danilo Krummrich <[email protected]> Cc: [email protected] Cc: [email protected] # v6.1+ Signed-off-by: Maarten Lankhorst <[email protected]> Cc: Matthew Brost <[email protected]> Acked-by: Mukesh Ojha <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> [ removed const qualifier from bin_attribute callback parameters ] Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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jira SECO-170
In Rocky9 if you run ./run_vmtests.sh -t hmm it will fail and cause an infinate loop on ASSERTs in FIXTURE_TEARDOWN()
This temporary fix is based on the discussion here https://patchwork.kernel.org/project/linux-kselftest/patch/[email protected]/#25046055
We will investigate further kselftest updates that will resolve the root causes of this.
Testing
Previously this would infinite loop