ALSA: timer: Fix master timer notification

commit 9c1fe96bded935369f8340c2ac2e9e189f697d5d upstream. snd_timer_notify1() calls the notification to each slave for a master event, but it passes a wrong event number. It should be +10 offset, corresponding to SNDRV_TIMER_EVENT_MXXX, but it's incorrectly with +100 offset. Casually this was spotted by UBSAN check via syzkaller. Reported-by: [email protected] Reviewed-by: Jaroslav Kysela <[email protected]> Cc: <[email protected]> Link: https://lore.kernel.org/r/[email protected] Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Takashi Iwai <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
OpenNuvoton · Oct 27, 2021 · 64393a7 · 64393a7
1 parent a01d443
commit 64393a7
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/sound/core/timer.c b/sound/core/timer.c
@@ -432,9 +432,10 @@ static void snd_timer_notify1(struct snd_timer_instance *ti, int event)
 		return;
 	if (timer->hw.flags & SNDRV_TIMER_HW_SLAVE)
 		return;
+	event += 10; /* convert to SNDRV_TIMER_EVENT_MXXX */
 	list_for_each_entry(ts, &ti->slave_active_head, active_list)
 		if (ts->ccallback)
-			ts->ccallback(ts, event + 100, &tstamp, resolution);
+			ts->ccallback(ts, event, &tstamp, resolution);
 }
 
 /* start/continue a master timer */