CVE-2026-80666 in Linux
Resumen
por VulDB • 2026-08-28
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad:
Bluetooth: sco: Corregir una condición de carrera en sco_sock_timeout()
sco_sock_timeout() se ejecuta asíncronamente y llama a lock_sk(sk). Si el socket está cerrándose mientras el temporizador está activo, mantiene el mismo bloqueo (lock_sk(sk)) dos veces, lo que provoca un punto muerto (deadlock).
CPU 0 CPU 1 ==================== ====================== sco_sock_close() sco_sock_timeout() lock_sk(sk) // <-- BLOQUEO __sco_sock_close() sco_chan_del() sco_conn_put() sco_conn_free() disable_delayed_work_sync() lock(sk) // <-- MISMO BLOQUEO
Corregir esto moviendo disable_delayed_work_sync() fuera de lock_sk(sk), asegurando que no se mantenga ningún lock_sk(sk) antes de sco_sock_timeout().
Splat de Lockdep:
ADVERTENCIA: posible dependencia circular de bloqueo detectada 6.13.0-rc4 #7 No contaminado (Not tainted)
syz-executor292/9514 está intentando adquirir el siguiente bloqueo: ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+}-{0:0}, en: rcu_lock_acquire sect/v6.13-rc4/./include/linux/rcupdate.h:337 [inline]
ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+}-{0:0}, en: rcu_read_lock sect/v6.13-rc4/./include/linux/rcupdate.h:849 [inline]
ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+}-{0:0}, en: start_flush_work sect/v6.13-rc4/kernel/workqueue.c:4137 [inline]
ffff8881115d5070 ((work_completion)(&(&conn->timeout_work)->work)){+.+}-{0:0}, en: __flush_work+0xd1/0xc40 sect/v6.13-rc4/kernel/workqueue.c:4195
pero la tarea ya está manteniendo el siguiente bloqueo: ffff88807db3a258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+}-{0:0}, en: lock_sk sect/v6.13-rc4/./include/net/sock.h:1623 [inline]
ffff88807db3a258 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+}-{0:0}, en: sco_sock_close+0x25/0x100 sect/v6.13-rc4/net/bluetooth/sco.c:524
el cual ya depende del nuevo bloqueo.
La cadena de dependencias existente (en orden inverso) es:
-> #1 (sk_lock-AF_BLUETOOTH-BTPROTO_SCO){+.+}-{0:0}:
lock_acquire+0x1c4/0x520 sect/v6.13-rc4/kernel/locking/lockdep.c:5849 lock_sk_nested+0x48/0x130 sect/v6.13-rc4/net/core/sock.c:3622 lock_sk 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/blue... ---truncado---
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