Bluetooth: sco: Fix a race condition in sco_sock_timeout()

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-80666
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-28 08:16:51 UTC
Updated2026-08-28 08:16:51 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: Bluetooth: sco: Fix a race condition in sco_sock_timeout() sco_sock_timeout() runs asynchronously and lock_sock(sk). If the socket is closing while the timer is running, it holds the same lock (lock_sock(sk)) twice, leading to a deadlock. CPU 0 CPU 1 ==================== ====================== sco_sock_close() sco_sock_timeout() lock_sock(sk) // <-- LOCK __sco_sock_close() sco_chan_del() sco_conn_put() sco_conn_free() disable_delayed_work_sync() lock(sk) // <-- SAME LOCK Fix this by moving disable_delayed_work_sync() outside of lock_sock(sk), ensuring that no lock_sock(sk) is held before sco_sock_timeout(). Lockdep splat: WARNING: possible circular locking dependency detected 6.13.0-rc4 #7 Not tainted syz-executor292/9514 is trying to acquire lock: ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire sect/v6.13-rc4/./include/linux/rcupdate.h:337 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: rcu_read_lock sect/v6.13-rc4/./include/linux/rcupdate.h:849 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: start_flush_work sect/v6.13-rc4/kernel/workqueue.c:4137 [inline] ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}, at: __flush_work+0xd1/0xc40 sect/v6.13-rc4/kernel/workqueue.c:4195 but task is already holding lock: ffff88807db3a258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: lock_sock sect/v6.13-rc4/./include/net/sock.h:1623 [inline] ffff88807db3a258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}, at: sco_sock_close+0x25/0x100 sect/v6.13-rc4/net/bluetooth/sco.c:524 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+.}-{0:0}: lock_acquire+0x1c4/0x520 sect/v6.13-rc4/kernel/locking/lockdep.c:5849 lock_sock_nested+0x48/0x130 sect/v6.13-rc4/net/core/sock.c:3622 lock_sock sect/v6.13-rc4/./include/net/sock.h:1623 [inline] sco_sock_timeout+0xbe/0x270 sect/v6.13-rc4/net/bluetooth/sco.c:158 process_one_work sect/v6.13-rc4/kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa99/0x18f0 sect/v6.13-rc4/kernel/workqueue.c:3310 worker_thread+0x8a9/0xd80 sect/v6.13-rc4/kernel/workqueue.c:3391 kthread+0x2c6/0x360 sect/v6.13-rc4/kernel/kthread.c:389 ret_from_fork+0x4e/0x80 sect/v6.13-rc4/arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 sect/v6.13-rc4/arch/x86/entry/entry_64.S:244 -> #0 ((work_completion)(&(&conn->timeout_work)->work)){+.+.}-{0:0}: check_prev_add sect/v6.13-rc4/kernel/locking/lockdep.c:3161 [inline] check_prevs_add sect/v6.13-rc4/kernel/locking/lockdep.c:3280 [inline] validate_chain+0x1888/0x5760 sect/v6.13-rc4/kernel/locking/lockdep.c:3904 __lock_acquire+0x13b4/0x2120 sect/v6.13-rc4/kernel/locking/lockdep.c:5226 lock_acquire+0x1c4/0x520 sect/v6.13-rc4/kernel/locking/lockdep.c:5849 touch_work_lockdep_map sect/v6.13-rc4/kernel/workqueue.c:3909 [inline] start_flush_work sect/v6.13-rc4/kernel/workqueue.c:4163 [inline] __flush_work+0x70f/0xc40 sect/v6.13-rc4/kernel/workqueue.c:4195 __cancel_work_sync sect/v6.13-rc4/kernel/workqueue.c:4351 [inline] disable_delayed_work_sync+0xbb/0xf0 sect/v6.13-rc4/kernel/workqueue.c:4514 sco_conn_free sect/v6.13-rc4/net/bluetooth/sco.c:95 [inline] kref_put sect/v6.13-rc4/./include/linux/kref.h:65 [inline] sco_conn_put+0x18f/0x270 sect/v6.13-rc4/net/bluetooth/sco.c:107 sco_chan_del+0xe2/0x210 sect/v6.13-rc4/net/bluetooth/sco.c:236 sco_sock_close+0x8f/0x100 sect/v6.13-rc4/net/bluetooth/sco.c:526 sco_sock_release+0x62/0x2d0 sect/v6.13-rc4/net/blueto ---truncated---

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected e6720779ae612a14ac4ba7fe4fd5b27d900d932c da4d8eea0c5f33ea35c0e1d9e5f3e439f3b987ce git Not specified
CNA Linux Linux affected e6720779ae612a14ac4ba7fe4fd5b27d900d932c a50da115b5888062d32c86a548a29b4e2559d7ec git Not specified
CNA Linux Linux affected e6720779ae612a14ac4ba7fe4fd5b27d900d932c 0f8a5dcc66648b6e1458a9f3ba4c5a0463a228fc git Not specified
CNA Linux Linux affected 6.13 Not specified
CNA Linux Linux unaffected 6.13 semver Not specified
CNA Linux Linux unaffected 6.18.40 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.5 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/da4d8eea0c5f33ea35c0e1d9e5f3e439f3b987ce 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/a50da115b5888062d32c86a548a29b4e2559d7ec 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/0f8a5dcc66648b6e1458a9f3ba4c5a0463a228fc 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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