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| author |   Takashi Iwai <tiwai@suse.de> | 2020-01-29 20:59:07 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2020-01-29 21:01:19 +0100 |
| commit | 66f2d19f8116e16898f8d82e28573a384ddc430d (patch) | |
| tree | ce3be32aac7d4333c672af1a2af8babd7c47575b /sound/core | |
| parent | ALSA: uapi: Fix sparse warning (diff) | |
| download | wireguard-linux-66f2d19f8116e16898f8d82e28573a384ddc430d.tar.xz wireguard-linux-66f2d19f8116e16898f8d82e28573a384ddc430d.zip | |
ALSA: pcm: Fix memory leak at closing a stream without hw_free
ALSA PCM core recently introduced a new managed PCM buffer allocation
mode that does allocate / free automatically at hw_params and
hw_free. However, it overlooked the code path directly calling
hw_free PCM ops at releasing the PCM substream, and it may result in a
memory leak as spotted by syzkaller when no buffer preallocation is
used (e.g. vmalloc buffer).
This patch papers over it with a slight refactoring. The hw_free ops
call and relevant tasks are unified in a new helper function, and call
it from both places.
Fixes: 0dba808eae26 ("ALSA: pcm: Introduce managed buffer allocation mode")
Reported-by: syzbot+30edd0f34bfcdc548ac4@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200129195907.12197-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/pcm_native.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index bb23f5066654..4ac42ee1238c 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -786,10 +786,22 @@ end: return err; } +static int do_hw_free(struct snd_pcm_substream *substream) +{ + int result = 0; + + snd_pcm_sync_stop(substream); + if (substream->ops->hw_free) + result = substream->ops->hw_free(substream); + if (substream->managed_buffer_alloc) + snd_pcm_lib_free_pages(substream); + return result; +} + static int snd_pcm_hw_free(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime; - int result = 0; + int result; if (PCM_RUNTIME_CHECK(substream)) return -ENXIO; @@ -806,11 +818,7 @@ static int snd_pcm_hw_free(struct snd_pcm_substream *substream) snd_pcm_stream_unlock_irq(substream); if (atomic_read(&substream->mmap_count)) return -EBADFD; - snd_pcm_sync_stop(substream); - if (substream->ops->hw_free) - result = substream->ops->hw_free(substream); - if (substream->managed_buffer_alloc) - snd_pcm_lib_free_pages(substream); + result = do_hw_free(substream); snd_pcm_set_state(substream, SNDRV_PCM_STATE_OPEN); pm_qos_remove_request(&substream->latency_pm_qos_req); return result; @@ -2529,9 +2537,7 @@ void snd_pcm_release_substream(struct snd_pcm_substream *substream) snd_pcm_drop(substream); if (substream->hw_opened) { - if (substream->ops->hw_free && - substream->runtime->status->state != SNDRV_PCM_STATE_OPEN) - substream->ops->hw_free(substream); + do_hw_free(substream); substream->ops->close(substream); substream->hw_opened = 0; } |