Commit 9c1fe96b authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: timer: Fix master timer notification 



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: default avatar <syzbot+d102fa5b35335a7e544e@syzkaller.appspotmail.com>
Reviewed-by: default avatarJaroslav Kysela <perex@perex.cz>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/000000000000e5560e05c3bd1d63@google.com
Link: https://lore.kernel.org/r/20210602113823.23777-1-tiwai@suse.de


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent 3ae72f6a

sound/core/timer.c

+2 −1
Original line number Diff line number Diff line
@@ -520,9 +520,10 @@ 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 */