From: Takashi Iwai Date: Tue, 22 Mar 2022 17:13:25 +0000 (+0100) Subject: ALSA: pcm: Add stream lock during PCM reset ioctl operations X-Git-Tag: v4.14.274~12 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=11a63e57e4b9cba31c1e3ca6529438d837552908;p=thirdparty%2Fkernel%2Fstable.git ALSA: pcm: Add stream lock during PCM reset ioctl operations 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: Reviewed-by: Jaroslav Kysela Link: https://lore.kernel.org/r/20220322171325.4355-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index c78db361cbbaa..c530d008fe01d 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1616,21 +1616,25 @@ static int snd_pcm_do_reset(struct snd_pcm_substream *substream, int state) 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 = {