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authorTakashi Iwai <tiwai@suse.de>2020-01-29 20:59:07 +0100
committerTakashi Iwai <tiwai@suse.de>2020-01-29 21:01:19 +0100
commit66f2d19f8116e16898f8d82e28573a384ddc430d (patch)
treece3be32aac7d4333c672af1a2af8babd7c47575b /sound
parent46b770f720bdd8a7de1c04a1cab5d4e9e21d6666 (diff)
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')
-rw-r--r--sound/core/pcm_native.c24
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;
}