Bluetooth: Fix use-after-free in hci_remove_ltk/hci_remove_irk

Similar to commit 0f7d9b3 ("netfilter: nf_tables: fix use-after-free
in nft_set_catchall_destroy()"). We can not access k after kfree_rcu()
call.

Cc: [email protected]
Signed-off-by: Min Li <[email protected]>
Signed-off-by: Luiz Augusto von Dentz <[email protected]>

Author: Vudentz

net/bluetooth/hci_core.c

@@ -1416,10 +1416,10 @@ int hci_remove_link_key(struct hci_dev *hdev, bdaddr_t *bdaddr)
 
 int hci_remove_ltk(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 bdaddr_type)
 {
-	struct smp_ltk *k;
+	struct smp_ltk *k, *tmp;
 	int removed = 0;
 
-	list_for_each_entry_rcu(k, &hdev->long_term_keys, list) {
+	list_for_each_entry_safe(k, tmp, &hdev->long_term_keys, list) {
 		if (bacmp(bdaddr, &k->bdaddr) || k->bdaddr_type != bdaddr_type)
 			continue;
 
@@ -1435,9 +1435,9 @@ int hci_remove_ltk(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 bdaddr_type)
 
 void hci_remove_irk(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 addr_type)
 {
-	struct smp_irk *k;
+	struct smp_irk *k, *tmp;
 
-	list_for_each_entry_rcu(k, &hdev->identity_resolving_keys, list) {
+	list_for_each_entry_safe(k, tmp, &hdev->identity_resolving_keys, list) {
 		if (bacmp(bdaddr, &k->bdaddr) || k->addr_type != addr_type)
 			continue;