[PATCH 6.1 0350/1146] ASoC: amd: acp: Fix possible UAF in acp_dma_open

Greg Kroah-Hartman
2022-12-28T15:44:53Z

From: Gaosheng Cui <cuigaosheng1@huawei.com>

[ Upstream commit 3420fdb8ae99f0a08d78d2b80f42a71971cf478d ]

Smatch report warning as follows:

sound/soc/amd/acp/acp-platform.c:199 acp_dma_open() warn:
'&stream->list' not removed from list

If snd_pcm_hw_constraint_integer() fails in acp_dma_open(),
stream will be freed, but stream->list will not be removed from
adata->stream_list, then list traversal may cause UAF.

Fix by adding the newly allocated stream to the list once it's fully
initialised.

Fixes: 7929985cfe36 ("ASoC: amd: acp: Initialize list to store acp_stream during pcm_open")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Link: https://lore.kernel.org/r/20221118030056.3135960-1-cuigaosheng1@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/amd/acp/acp-platform.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/sound/soc/amd/acp/acp-platform.c b/sound/soc/amd/acp/acp-platform.c
index 85a81add4ef9..447612a7a762 100644
--- a/sound/soc/amd/acp/acp-platform.c
+++ b/sound/soc/amd/acp/acp-platform.c
@@ -184,10 +184,6 @@ static int acp_dma_open(struct snd_soc_component *component, struct snd_pcm_subs

stream->substream = substream;

- spin_lock_irq(&adata->acp_lock);
- list_add_tail(&stream->list, &adata->stream_list);
- spin_unlock_irq(&adata->acp_lock);
-
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
runtime->hw = acp_pcm_hardware_playback;
else
@@ -203,6 +199,10 @@ static int acp_dma_open(struct snd_soc_component *component, struct snd_pcm_subs

writel(1, ACP_EXTERNAL_INTR_ENB(adata));

+ spin_lock_irq(&adata->acp_lock);
+ list_add_tail(&stream->list, &adata->stream_list);
+ spin_unlock_irq(&adata->acp_lock);
+
return ret;
}

--
2.35.1