[PATCH] ASoC: soc-compress: prevent the potentially use of null pointer

[Jiasheng Jiang]

The codec_dai and the cpu_dai are from rtd. When the rtd->dais[0]
or rtd->dais[rtd->num_cpus] is None, it could lead to the use of
null pointer in the snd_soc_dai_stream_valid(). So it might be better
to add the check before the use of snd_soc_dai_stream_valid().

Fixes: 467fece ("ASoC: soc-dai: move snd_soc_dai_stream_valid() to soc-dai.c")
Signed-off-by: Jiasheng Jiang <jiasheng at iscas.ac.cn>
---
 sound/soc/soc-compress.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/sound/soc/soc-compress.c b/sound/soc/soc-compress.c
index b4f5935..67c3df1 100644
--- a/sound/soc/soc-compress.c
+++ b/sound/soc/soc-compress.c
@@ -535,12 +535,14 @@ int snd_soc_new_compress(struct snd_soc_pcm_runtime *rtd, int num)
 	}
 
 	/* check client and interface hw capabilities */
-	if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK) &&
-	    snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_PLAYBACK))
-		playback = 1;
-	if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE) &&
-	    snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_CAPTURE))
-		capture = 1;
+	if (codec_dai && cpu_dai) {
+		if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK) &&
+		    snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_PLAYBACK))
+			playback = 1;
+		if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE) &&
+		    snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_CAPTURE))
+			capture = 1;
+	}
 
 	/*
 	 * Compress devices are unidirectional so only one of the directions
-- 
2.7.4