CVE-2024-38600

In the Linux kernel, the following vulnerability has been resolved: ALSA:
Fix deadlocks with kctl removals at disconnection In snd_card_disconnect(),
we set card->shutdown flag at the beginning, call callbacks and do sync for
card->power_ref_sleep waiters at the end. The callback may delete a kctl
element, and this can lead to a deadlock when the device was in the
suspended state. Namely: * A process waits for the power up at
snd_power_ref_and_wait() in snd_ctl_info() or read/write() inside
card->controls_rwsem. * The system gets disconnected meanwhile, and the
driver tries to delete a kctl via snd_ctl_remove*(); it tries to take
card->controls_rwsem again, but this is already locked by the above. Since
the sleeper isn’t woken up, this deadlocks. An easy fix is to wake up
sleepers before processing the driver disconnect callbacks but right after
setting the card->shutdown flag. Then all sleepers will abort immediately,
and the code flows again. So, basically this patch moves the wait_event()
call at the right timing. While we’re at it, just to be sure, call
wait_event_all() instead of wait_event(), although we don’t use exclusive
events on this queue for now.