Commit 0c4f09ce authored Nov 11, 2019 by Takashi Iwai

ALSA: timer: Fix the breakage of slave link open

A silly mistake was made while applying the fix for potential races in
commit 6a34367e ("ALSA: timer: Fix possible race at assigning a
timer instance"): when a slave PCM is opened and succeeds, it doesn't
return but proceeds to the master timer open code instead. Plug the
hole and beautify a bit.

Fixes: 6a34367e ("ALSA: timer: Fix possible race at assigning a timer instance")
Reported-by: <syzbot+4476917c053f60112c99@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/r/20191111173642.6093-1-tiwai@suse.de

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

parent 2bc1e1fd

sound/core/timer.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -268,8 +268,7 @@ int snd_timer_open(struct snd_timer_instance *timeri,
		list_add_tail(&timeri->open_list, &snd_timer_slave_list);
		num_slaves++;
		err = snd_timer_check_slave(timeri);
		if (err < 0)
		goto close;
		goto list_added;
		}

		/* open a master instance */
		@@ -324,7 +323,7 @@ int snd_timer_open(struct snd_timer_instance *timeri,
		list_add_tail(&timeri->open_list, &timer->open_list_head);
		timer->num_instances++;
		err = snd_timer_check_master(timeri);
		close:
		list_added:
		if (err < 0)
		snd_timer_close_locked(timeri, &card_dev_to_put);