ALSA: echoaudio: Prevent races in calls to set_audio_format()

The function uses chip->comm_page which needs locking against
other use at the same time.

Signed-off-by: Mark Hills <mark@xwax.org>
Link: https://lore.kernel.org/r/20200708101848.3457-3-mark@xwax.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Mark Hills 2020-07-08 11:18:46 +01:00 committed by Takashi Iwai
parent 027c70021b
commit 6c33125448

View File

@ -711,9 +711,22 @@ static int pcm_prepare(struct snd_pcm_substream *substream)
if (snd_BUG_ON(pipe_index >= px_num(chip)))
return -EINVAL;
if (snd_BUG_ON(!is_pipe_allocated(chip, pipe_index)))
/*
* We passed checks we can do independently; now take
* exclusive control
*/
spin_lock_irq(&chip->lock);
if (snd_BUG_ON(!is_pipe_allocated(chip, pipe_index))) {
spin_unlock(&chip->lock);
return -EINVAL;
}
set_audio_format(chip, pipe_index, &format);
spin_unlock_irq(&chip->lock);
return 0;
}