bonding: check xdp prog when set bond mode

JIRA: https://issues.redhat.com/browse/RHEL-96600
Upstream Status: net.git commit 094ee60

commit 094ee60
Author: Wang Liang <[email protected]>
Date:   Fri Mar 21 12:48:52 2025 +0800

    bonding: check xdp prog when set bond mode

    Following operations can trigger a warning[1]:

        ip netns add ns1
        ip netns exec ns1 ip link add bond0 type bond mode balance-rr
        ip netns exec ns1 ip link set dev bond0 xdp obj af_xdp_kern.o sec xdp
        ip netns exec ns1 ip link set bond0 type bond mode broadcast
        ip netns del ns1

    When delete the namespace, dev_xdp_uninstall() is called to remove xdp
    program on bond dev, and bond_xdp_set() will check the bond mode. If bond
    mode is changed after attaching xdp program, the warning may occur.

    Some bond modes (broadcast, etc.) do not support native xdp. Set bond mode
    with xdp program attached is not good. Add check for xdp program when set
    bond mode.

        [1]
        ------------[ cut here ]------------
        WARNING: CPU: 0 PID: 11 at net/core/dev.c:9912 unregister_netdevice_many_notify+0x8d9/0x930
        Modules linked in:
        CPU: 0 UID: 0 PID: 11 Comm: kworker/u4:0 Not tainted 6.14.0-rc4 #107
        Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
        Workqueue: netns cleanup_net
        RIP: 0010:unregister_netdevice_many_notify+0x8d9/0x930
        Code: 00 00 48 c7 c6 6f e3 a2 82 48 c7 c7 d0 b3 96 82 e8 9c 10 3e ...
        RSP: 0018:ffffc90000063d80 EFLAGS: 00000282
        RAX: 00000000ffffffa1 RBX: ffff888004959000 RCX: 00000000ffffdfff
        RDX: 0000000000000000 RSI: 00000000ffffffea RDI: ffffc90000063b48
        RBP: ffffc90000063e28 R08: ffffffff82d39b28 R09: 0000000000009ffb
        R10: 0000000000000175 R11: ffffffff82d09b40 R12: ffff8880049598e8
        R13: 0000000000000001 R14: dead000000000100 R15: ffffc90000045000
        FS:  0000000000000000(0000) GS:ffff888007a00000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
        CR2: 000000000d406b60 CR3: 000000000483e000 CR4: 00000000000006f0
        Call Trace:
         <TASK>
         ? __warn+0x83/0x130
         ? unregister_netdevice_many_notify+0x8d9/0x930
         ? report_bug+0x18e/0x1a0
         ? handle_bug+0x54/0x90
         ? exc_invalid_op+0x18/0x70
         ? asm_exc_invalid_op+0x1a/0x20
         ? unregister_netdevice_many_notify+0x8d9/0x930
         ? bond_net_exit_batch_rtnl+0x5c/0x90
         cleanup_net+0x237/0x3d0
         process_one_work+0x163/0x390
         worker_thread+0x293/0x3b0
         ? __pfx_worker_thread+0x10/0x10
         kthread+0xec/0x1e0
         ? __pfx_kthread+0x10/0x10
         ? __pfx_kthread+0x10/0x10
         ret_from_fork+0x2f/0x50
         ? __pfx_kthread+0x10/0x10
         ret_from_fork_asm+0x1a/0x30
         </TASK>
        ---[ end trace 0000000000000000 ]---

    Fixes: 9e2ee5c ("net, bonding: Add XDP support to the bonding driver")
    Signed-off-by: Wang Liang <[email protected]>
    Acked-by: Jussi Maki <[email protected]>
    Reviewed-by: Nikolay Aleksandrov <[email protected]>
    Reviewed-by: Toke Høiland-Jørgensen <[email protected]>
    Link: https://patch.msgid.link/[email protected]
    Signed-off-by: Jakub Kicinski <[email protected]>

Signed-off-by: Hangbin Liu <[email protected]>

Author: Hangbin Liu

drivers/net/bonding/bond_main.c

@@ -322,9 +322,9 @@ static bool bond_sk_check(struct bonding *bond)
 	}
 }
 
-static bool bond_xdp_check(struct bonding *bond)
+bool bond_xdp_check(struct bonding *bond, int mode)
 {
-	switch (BOND_MODE(bond)) {
+	switch (mode) {
 	case BOND_MODE_ROUNDROBIN:
 	case BOND_MODE_ACTIVEBACKUP:
 		return true;
@@ -1934,7 +1934,7 @@ void bond_xdp_set_features(struct net_device *bond_dev)
 
 	ASSERT_RTNL();
 
-	if (!bond_xdp_check(bond) || !bond_has_slaves(bond)) {
+	if (!bond_xdp_check(bond, BOND_MODE(bond)) || !bond_has_slaves(bond)) {
 		xdp_clear_features_flag(bond_dev);
 		return;
 	}
@@ -5696,7 +5696,7 @@ static int bond_xdp_set(struct net_device *dev, struct bpf_prog *prog,
 
 	ASSERT_RTNL();
 
-	if (!bond_xdp_check(bond)) {
+	if (!bond_xdp_check(bond, BOND_MODE(bond))) {
 		BOND_NL_ERR(dev, extack,
 			    "No native XDP support for the current bonding mode");
 		return -EOPNOTSUPP;

drivers/net/bonding/bond_options.c

@@ -868,6 +868,9 @@ static bool bond_set_xfrm_features(struct bonding *bond)
 static int bond_option_mode_set(struct bonding *bond,
 				const struct bond_opt_value *newval)
 {
+	if (bond->xdp_prog && !bond_xdp_check(bond, newval->value))
+		return -EOPNOTSUPP;
+
 	if (!bond_mode_uses_arp(newval->value)) {
 		if (bond->params.arp_interval) {
 			netdev_dbg(bond->dev, "%s mode is incompatible with arp monitoring, start mii monitoring\n",

include/net/bonding.h

@@ -695,6 +695,7 @@ void bond_debug_register(struct bonding *bond);
 void bond_debug_unregister(struct bonding *bond);
 void bond_debug_reregister(struct bonding *bond);
 const char *bond_mode_name(int mode);
+bool bond_xdp_check(struct bonding *bond, int mode);
 void bond_setup(struct net_device *bond_dev);
 unsigned int bond_get_num_tx_queues(void);
 int bond_netlink_init(void);