[PATCH 5.14 741/849] ALSA: memalloc: Catch call with NULL snd_dma_buffer pointer

Greg Kroah-Hartman
2021-11-15T23:21:52Z

From: Takashi Iwai <tiwai@suse.de>

[ Upstream commit dce9446192439eaac81c21f517325fb473735e53 ]

Although we've covered all calls with NULL dma buffer pointer, so far,
there may be still some else in the wild. For catching such a case
more easily, add a WARN_ON_ONCE() in snd_dma_get_ops().

Fixes: 37af81c5998f ("ALSA: core: Abstract memory alloc helpers")
Link: https://lore.kernel.org/r/20211105102103.28148-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/core/memalloc.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/sound/core/memalloc.c b/sound/core/memalloc.c
index 05e3a2bcbea7d..fcb082b4e6bd3 100644
--- a/sound/core/memalloc.c
+++ b/sound/core/memalloc.c
@@ -403,6 +403,8 @@ static const struct snd_malloc_ops *dma_ops[] = {

static const struct snd_malloc_ops *snd_dma_get_ops(struct snd_dma_buffer *dmab)
{
+ if (WARN_ON_ONCE(!dmab))
+ return NULL;
if (WARN_ON_ONCE(dmab->dev.type <= SNDRV_DMA_TYPE_UNKNOWN ||
dmab->dev.type >= ARRAY_SIZE(dma_ops)))
return NULL;
--
2.33.0