Re: [syzbot] [sound?] possible deadlock in snd_timer_close_locked

[Hillf Danton]

On Fri, 15 Mar 2024 04:16:27 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13a304a5180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  master

--- x/sound/core/timer.c
+++ y/sound/core/timer.c
@@ -409,8 +409,9 @@ static void snd_timer_close_locked(struc
 	struct snd_timer *timer = timeri->timer;
 
 	if (timer) {
-		guard(spinlock)(&timer->lock);
+		spin_lock_irq(&timer->lock);
 		timeri->flags |= SNDRV_TIMER_IFLG_DEAD;
+		spin_unlock_irq(&timer->lock);
 	}
 
 	if (!list_empty(&timeri->open_list)) {
--