From: Takashi Iwai <tiwai@xxxxxxx> 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@xxxxxxxxxxxxxxx> Reviewed-by: Jaroslav Kysela <perex@xxxxxxxx> Link: https://lore.kernel.org/r/20220322171325.4355-1-tiwai@xxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/core/pcm_native.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1489,21 +1489,25 @@ static int snd_pcm_do_reset(struct snd_p int err = substream->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; } static void snd_pcm_post_reset(struct snd_pcm_substream *substream, int 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 = { Patches currently in stable-queue which might be from tiwai@xxxxxxx are queue-4.9/alsa-cmipci-restore-aux-vol-on-suspend-resume.patch queue-4.9/alsa-usb-audio-add-mute-tlv-for-playback-volumes-on-rode-nt-usb.patch queue-4.9/alsa-pci-fix-reading-of-swapped-values-from-pcmreg-in-ac97-codec.patch queue-4.9/alsa-pcm-add-stream-lock-during-pcm-reset-ioctl-operations.patch
