ASoC: soc-compress.c: fix NULL dereference

In soc_new_compress() when rtd->dai_link->dynamic 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 using rtd->dai_link->dpcm_playback and rtd->dai_link->dpcm_capture as
playback_count and capture_count to snd_pcm_new_internal().

Signed-off-by: Qais Yousef <qais.yousef@imgtec.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

1 files changed, 6 insertions, 3 deletions

diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
index 590a82f01d0b..025c38fbe3c0 100644
--- a/sound/soc/soc-compress.c
+++ b/sound/soc/soc-compress.c
@@ -659,7 +659,8 @@ int soc_new_compress(struct snd_soc_pcm_runtime *rtd, int num)
                         rtd->dai_link->stream_name);
 
                 ret = snd_pcm_new_internal(rtd->card->snd_card, new_name, num,
-                                1, 0, &be_pcm);
+                                rtd->dai_link->dpcm_playback,
+                                rtd->dai_link->dpcm_capture, &be_pcm);
                 if (ret < 0) {
                         dev_err(rtd->card->dev, "ASoC: can't create compressed for %s\n",
                                 rtd->dai_link->name);
@@ -668,8 +669,10 @@ 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;
+                if (rtd->dai_link->dpcm_playback)
+                        be_pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream->private_data = rtd;
+                else if (rtd->dai_link->dpcm_capture)
+                        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));