[PATCH 5.0 098/122] ASoC: dpcm: skip missing substream while applying symmetry

From: Greg Kroah-Hartman
Date: Mon May 06 2019 - 10:38:28 EST

From: Jerome Brunet <jbrunet@xxxxxxxxxxxx>

commit 6246f283d5e02ac757bd8d9bacde8fdc54c4582d upstream.

If for any reason, the backend does not have the requested substream
(like capture on a playback only backend), the BE will be skipped in

However, dpcm_apply_symmetry() does not skip those BE and will
dereference the be_substream (NULL) pointer anyway.

Like in dpcm_be_dai_startup(), just skip those BE.

Fixes: 906c7d690c3b ("ASoC: dpcm: Apply symmetry for DPCM")
Signed-off-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

sound/soc/soc-pcm.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -1895,10 +1895,15 @@ static int dpcm_apply_symmetry(struct sn
struct snd_soc_pcm_runtime *be = dpcm->be;
struct snd_pcm_substream *be_substream =
snd_soc_dpcm_get_substream(be, stream);
- struct snd_soc_pcm_runtime *rtd = be_substream->private_data;
+ struct snd_soc_pcm_runtime *rtd;
struct snd_soc_dai *codec_dai;
int i;

+ /* A backend may not have the requested substream */
+ if (!be_substream)
+ continue;
+ rtd = be_substream->private_data;
if (rtd->dai_link->be_hw_params_fixup)