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: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent 67ada836

sound/core/timer.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -531,6 +531,8 @@ int snd_timer_stop(struct snd_timer_instance *timeri)
	if (err < 0)		if (err < 0)
	return err;		return err;
	timer = timeri->timer;		timer = timeri->timer;
			if (!timer)
			return -EINVAL;
	spin_lock_irqsave(&timer->lock, flags);		spin_lock_irqsave(&timer->lock, flags);
	timeri->cticks = timeri->ticks;		timeri->cticks = timeri->ticks;
	timeri->pticks = 0;		timeri->pticks = 0;