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From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     vkoul@kernel.org, lgirdwood@gmail.com, broonie@kernel.org,
        perex@perex.cz, tiwai@suse.com, alsa-devel@alsa-project.org
Cc:     linux-kernel@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH] ASoC: soc-compress: prevent the potentially use of null pointer
Date:   Wed, 13 Oct 2021 09:17:44 +0000
Message-Id: <1634116664-1784856-1-git-send-email-jiasheng@iscas.ac.cn>
Precedence: bulk

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@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