[PATCH] ALSA: ASoC: soc-compress.c: fix NULL dereference

From: Qais Yousef
Date: Tue Dec 23 2014 - 04:10:19 EST


In soc_new_compress() when rtd->dai_link->daynmic is set, we create the pcm
substreams with this call:

ret = snd_pcm_new_internal(rtd->card->snd_card, new_name, num,
1, 0, &be_pcm);

which passes 0 as capture_count leading to

be_pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream

being NULL, hence when trying to set rtd a few lines below we get an oops.
Fix by removing this line of code since CAPTURE substream will always be NULL.

Signed-off-by: Qais Yousef <qais.yousef@xxxxxxxxxx>
Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
Cc: Liam Girdwood <lgirdwood@xxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Jaroslav Kysela <perex@xxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
Not sure if this is the correct fix but that's what I could come up with my
limited knowledge.

I think the more correct solution would be to use the value of
rtd->dai_link->dpcm_playback and rtd->dai_link->dpcm_capture in the args of
snd_pcm_new_internal() for playback_count and capture_count.

sound/soc/soc-compress.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
index 590a82f01d0b..7ab39f65384c 100644
--- a/sound/soc/soc-compress.c
+++ b/sound/soc/soc-compress.c
@@ -669,7 +669,6 @@ int soc_new_compress(struct snd_soc_pcm_runtime *rtd, int num)
rtd->pcm = be_pcm;
rtd->fe_compr = 1;
be_pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->private_data = rtd;
- be_pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream->private_data = rtd;
memcpy(compr->ops, &soc_compr_dyn_ops, sizeof(soc_compr_dyn_ops));
} else
memcpy(compr->ops, &soc_compr_ops, sizeof(soc_compr_ops));
--
2.1.0

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