There is one call trace that snd_soc_register_card() ->snd_soc_bind_card()->soc_init_pcm_runtime() ->snd_soc_dai_compress_new()->snd_soc_new_compress(). In the trace the 'codec_dai' transfers from card->dai_link, and we can see from the snd_soc_add_pcm_runtime() in snd_soc_bind_card() that, if value of card->dai_link->num_codecs is 0, then 'codec_dai' could be null pointer caused by index out of bound in 'asoc_rtd_to_codec(rtd, 0)'. And snd_soc_register_card() is called by various platforms. Therefore, it is better to add the check in the case of misusing. And because 'cpu_dai' has already checked in soc_init_pcm_runtime(), there is no need to check again. Adding the check as follow, then if 'codec_dai' is null, snd_soc_new_compress() will not pass through the check 'if (playback + capture != 1)', avoiding the leftover use of 'codec_dai'.

Fixes: 467fece ("ASoC: soc-dai: move snd_soc_dai_stream_valid() to soc-dai.c") Signed-off-by: Jiasheng Jiang jiasheng@iscas.ac.cn Reported-by: kernel test robot lkp@intel.com Reported-by: Dan Carpenter dan.carpenter@oracle.com --- 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) { + 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