CVE-2024-26886: Bluetooth: af_bluetooth: Fix deadlock

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-17 · updated 2026-10-30
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: af_bluetooth: Fix deadlock Attemting to do sock_lock on .recvmsg may cause a deadlock as shown bellow, so instead of using sock_sock this uses sk_receive_queue.lock on bt_sock_ioctl to avoid the UAF: INFO: task kworker/u9:1:121 blocked for more than 30 seconds. Not tainted 6.7.6-lemon #183 Workqueue: hci0 hci_rx_work Call Trace: <TASK> __schedule+0x37d/0xa00 schedule+0x32/0xe0 __lock_sock+0x68/0xa0 ? __pfx_autoremove_wake_function+0x10/0x10 lock_sock_nested+0x43/0x50 l2cap_sock_recv_cb+0x21/0xa0 l2cap_recv_frame+0x55b/0x30a0 ? psi_task_switch+0xeb/0x270 ? finish_task_switch.isra.0+0x93/0x2a0 hci_rx_work+0x33a/0x3f0 process_one_work+0x13a/0x2f0 worker_thread+0x2f0/0x410 ? __pfx_worker_thread+0x10/0x10 kthread+0xe0/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK>

Affected products

Linux kernel: from 5.10.206 before 5.11; from 5.15.146 before 5.16; from 6.1.70 before 6.1.83; from 6.6.9 before 6.6.23; from 6.7 before 6.7.11; from 6.8 before 6.8.2 — fixed in 5.11, 5.16, 6.1.83, 6.6.23, 6.7.11, 6.8.2
Linux: from 5.15.146 before 5.15.209; from 6.1.70 before 6.1.191; from 6.6.9 before 6.6.23; from 5.10.206 before 5.11 — fixed in 5.15.209, 6.1.191, 6.6.23, 5.11

How to fix

Upgrade to a fixed version: Linux kernel 5.11, 5.16, 6.1.83, 6.6.23; Linux 5.15.209, 6.1.191, 6.6.23, 5.11. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2024-26886 or the next vulnerability affects your stack