From: Takashi Iwai <tiwai@xxxxxxx> 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: syzbot+d102fa5b35335a7e544e@xxxxxxxxxxxxxxxxxxxxxxxxx Reviewed-by: Jaroslav Kysela <perex@xxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/000000000000e5560e05c3bd1d63@xxxxxxxxxx Link: https://lore.kernel.org/r/20210602113823.23777-1-tiwai@xxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/core/timer.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/sound/core/timer.c +++ b/sound/core/timer.c @@ -500,9 +500,10 @@ static void snd_timer_notify1(struct snd 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 */
