ALSA: timer - Fix Oops at closing slave timer

A slave-timer instance has no timer reference, and this results in NULL-dereference at stopping the timer, typically called at closing the device. Reference: https://bugzilla.kernel.org/show_bug.cgi?id=40682 Cc: <[email protected]> Signed-off-by: Takashi Iwai <[email protected]>
hjking · Aug 8, 2011 · 0584ffa · 0584ffa
1 parent 67ada83
commit 0584ffa
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/sound/core/timer.c b/sound/core/timer.c
@@ -531,6 +531,8 @@ int snd_timer_stop(struct snd_timer_instance *timeri)
 	if (err < 0)
 		return err;
 	timer = timeri->timer;
+	if (!timer)
+		return -EINVAL;
 	spin_lock_irqsave(&timer->lock, flags);
 	timeri->cticks = timeri->ticks;
 	timeri->pticks = 0;