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ALSA: pcm: Check for null pointer of pointer substream before dereferencing it 

[ Upstream commit 011b559be8 ]

Pointer substream is being dereferenced on the assignment of pointer card
before substream is being null checked with the macro PCM_RUNTIME_CHECK.
Although PCM_RUNTIME_CHECK calls BUG_ON, it still is useful to perform the
the pointer check before card is assigned.

Fixes: d4cfb30fce ("ALSA: pcm: Set per-card upper limit of PCM buffer allocations")
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20220424205945.1372247-1-colin.i.king@gmail.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Colin Ian King 2022-04-24 21:59:45 +01:00 committed by Greg Kroah-Hartman
parent 6521011b8d
commit 1f2e28857b
1 changed files with 2 additions and 1 deletions
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3
sound/core/pcm_memory.c
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@ -453,7 +453,6 @@ EXPORT_SYMBOL(snd_pcm_lib_malloc_pages);
*/
int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
{
struct snd_card *card = substream->pcm->card;
struct snd_pcm_runtime *runtime;
if (PCM_RUNTIME_CHECK(substream))
@ -462,6 +461,8 @@ int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream)
if (runtime->dma_area == NULL)
return 0;
if (runtime->dma_buffer_p != &substream->dma_buffer) {
struct snd_card *card = substream->pcm->card;
/* it's a newly allocated buffer. release it now. */
do_free_pages(card, runtime->dma_buffer_p);
kfree(runtime->dma_buffer_p);