In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: ISO: avoid deadlocks in iso_sock_timeout
iso_sock_timeout() takes lock_sock, so sync disabling the timer while holding that lock may deadlock.
iso_sock_timeout() may also run concurrently with iso_conn_del(), which leads to UAF
[Task 1] [Task hdev->workqueue]
iso_sock_timeout iso_conn_del
iso_conn_hold_unless_zero iso_chan_del
`------------> iso_conn_put
caller frees hcon
iso_conn_put
iso_conn_free
conn->hcon->iso_data = NULL; /* UAF */
Fix the deadlock by removing the disable from the lock_sock sections. Move the timer from iso_conn to iso_pinfo to decouple it from iso_conn which may need to be freed in lock_sock section. Convert some of the clear_timer to disable_timer.