From: Takashi Iwai tiwai@suse.de
commit 1f68915b2efd0d6bfd6e124aa63c94b3c69f127c upstream.
snd_pcm_reset() is a non-atomic operation, and it's allowed to run during the PCM stream running. It implies that the manipulation of hw_ptr and other parameters might be racy.
This patch adds the PCM stream lock at appropriate places in snd_pcm_*_reset() actions for covering that.
Cc: stable@vger.kernel.org Reviewed-by: Jaroslav Kysela perex@perex.cz Link: https://lore.kernel.org/r/20220322171325.4355-1-tiwai@suse.de Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- sound/core/pcm_native.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1850,11 +1850,13 @@ static int snd_pcm_do_reset(struct snd_p int err = snd_pcm_ops_ioctl(substream, SNDRV_PCM_IOCTL1_RESET, NULL); if (err < 0) return err; + snd_pcm_stream_lock_irq(substream); runtime->hw_ptr_base = 0; runtime->hw_ptr_interrupt = runtime->status->hw_ptr - runtime->status->hw_ptr % runtime->period_size; runtime->silence_start = runtime->status->hw_ptr; runtime->silence_filled = 0; + snd_pcm_stream_unlock_irq(substream); return 0; }
@@ -1862,10 +1864,12 @@ static void snd_pcm_post_reset(struct sn snd_pcm_state_t state) { struct snd_pcm_runtime *runtime = substream->runtime; + snd_pcm_stream_lock_irq(substream); runtime->control->appl_ptr = runtime->status->hw_ptr; if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && runtime->silence_size > 0) snd_pcm_playback_silence(substream, ULONG_MAX); + snd_pcm_stream_unlock_irq(substream); }
static const struct action_ops snd_pcm_action_reset = {