ALSA: timer - Add NULL-check for invalid slave timer

Just to be sure.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
index 950eed0c098e..67ebf1c21c04 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -328,6 +328,8 @@ int snd_timer_close(struct snd_timer_instance *timeri)
                 mutex_unlock(&register_mutex);
         } else {
                 timer = timeri->timer;
+                if (snd_BUG_ON(!timer))
+                        goto out;
                 /* wait, until the active callback is finished */
                 spin_lock_irq(&timer->lock);
                 while (timeri->flags & SNDRV_TIMER_IFLG_CALLBACK) {
@@ -353,6 +355,7 @@ int snd_timer_close(struct snd_timer_instance *timeri)
                 }
                 mutex_unlock(&register_mutex);
         }
+ out:
         if (timeri->private_free)
                 timeri->private_free(timeri);
         kfree(timeri->owner);