CVE-2026-63945

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: ISO: serialize iso_sock_clear_timer with socket lock

iso_sock_close() calls iso_sock_clear_timer() before acquiring

lock_sock(sk).

iso_sock_clear_timer() reads iso_pi(sk)->conn twice without the

socket lock held:

if (!iso_pi(sk)->conn)

return;

cancel_delayed_work(&iso_pi(sk)->conn->timeout_work);

Concurrently, iso_conn_del() executes under lock_sock(sk) and calls

iso_chan_del(), which sets iso_pi(sk)->conn to NULL and may result in

the final reference to the connection being dropped:

CPU0 CPU1

---- ----

iso_sock_clear_timer()

if (conn != NULL) ... lock_sock(sk)

iso_chan_del()

iso_pi(sk)->conn = NULL

cancel_delayed_work(conn) /* NULL deref or UAF */

iso_pi(sk)->conn is not stable across the unlock window, causing a

NULL pointer dereference or use-after-free.

Serialize iso_sock_clear_timer() with the socket lock by moving it

inside lock_sock()/release_sock(), matching the pattern used in

iso_conn_del() and all other call sites.