If earlier opening of source graph fails (e.g. ADSP rejects due to
incorrect audioreach topology), the graph is closed and
"dai_data->graph[dai->id]" is assigned NULL.  Preparing the DAI for sink
graph continues though and next call to q6apm_lpass_dai_prepare()
receives dai_data->graph[dai->id]=NULL leading to NULL pointer
exception:

  qcom-apm gprsvc:service:2:1: Error (1) Processing 0x01001002 cmd
  qcom-apm gprsvc:service:2:1: DSP returned error[1001002] 1
  q6apm-lpass-dais 30000000.remoteproc:glink-edge:gpr:service@1:bedais: fail to start APM port 78
  q6apm-lpass-dais 30000000.remoteproc:glink-edge:gpr:service@1:bedais: ASoC: error at snd_soc_pcm_dai_prepare on TX_CODEC_DMA_TX_3: -22
  Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a8
  ...
  Call trace:
   q6apm_graph_media_format_pcm+0x48/0x120 (P)
   q6apm_lpass_dai_prepare+0x110/0x1b4
   snd_soc_pcm_dai_prepare+0x74/0x108
   __soc_pcm_prepare+0x44/0x160
   dpcm_be_dai_prepare+0x124/0x1c0

Fixes: 30ad723b93ad ("ASoC: qdsp6: audioreach: add q6apm lpass dai support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

---

Changes in v2:
1. Use approach suggested by Srini (you gave me some code, so shall I
   add Co-developed-by?)
---
 sound/soc/qcom/qdsp6/q6apm-lpass-dais.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c b/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
index a0d90462fd6a..20974f10406b 100644
--- a/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
+++ b/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
@@ -213,8 +213,10 @@ static int q6apm_lpass_dai_prepare(struct snd_pcm_substream *substream, struct s
 
 	return 0;
 err:
-	q6apm_graph_close(dai_data->graph[dai->id]);
-	dai_data->graph[dai->id] = NULL;
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		q6apm_graph_close(dai_data->graph[dai->id]);
+		dai_data->graph[dai->id] = NULL;
+	}
 	return rc;
 }
 
-- 
2.48.1

On Thu, 04 Sep 2025 12:18:50 +0200, Krzysztof Kozlowski wrote:
> If earlier opening of source graph fails (e.g. ADSP rejects due to
> incorrect audioreach topology), the graph is closed and
> "dai_data->graph[dai->id]" is assigned NULL.  Preparing the DAI for sink
> graph continues though and next call to q6apm_lpass_dai_prepare()
> receives dai_data->graph[dai->id]=NULL leading to NULL pointer
> exception:
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-next

Thanks!

[1/1] ASoC: qcom: q6apm-lpass-dais: Fix NULL pointer dereference if source graph failed
      commit: 68f27f7c7708183e7873c585ded2f1b057ac5b97

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

On 9/4/25 11:18 AM, Krzysztof Kozlowski wrote:
> If earlier opening of source graph fails (e.g. ADSP rejects due to
> incorrect audioreach topology), the graph is closed and
> "dai_data->graph[dai->id]" is assigned NULL.  Preparing the DAI for sink
> graph continues though and next call to q6apm_lpass_dai_prepare()
> receives dai_data->graph[dai->id]=NULL leading to NULL pointer
> exception:
> 
>   qcom-apm gprsvc:service:2:1: Error (1) Processing 0x01001002 cmd
>   qcom-apm gprsvc:service:2:1: DSP returned error[1001002] 1
>   q6apm-lpass-dais 30000000.remoteproc:glink-edge:gpr:service@1:bedais: fail to start APM port 78
>   q6apm-lpass-dais 30000000.remoteproc:glink-edge:gpr:service@1:bedais: ASoC: error at snd_soc_pcm_dai_prepare on TX_CODEC_DMA_TX_3: -22
>   Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a8
>   ...
>   Call trace:
>    q6apm_graph_media_format_pcm+0x48/0x120 (P)
>    q6apm_lpass_dai_prepare+0x110/0x1b4
>    snd_soc_pcm_dai_prepare+0x74/0x108
>    __soc_pcm_prepare+0x44/0x160
>    dpcm_be_dai_prepare+0x124/0x1c0
> 
> Fixes: 30ad723b93ad ("ASoC: qdsp6: audioreach: add q6apm lpass dai support")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> 
> ---
> 
> Changes in v2:
> 1. Use approach suggested by Srini (you gave me some code, so shall I
>    add Co-developed-by?)
don't worry about it.


LGTM,

Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>


--srini
> ---
>  sound/soc/qcom/qdsp6/q6apm-lpass-dais.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c b/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
> index a0d90462fd6a..20974f10406b 100644
> --- a/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
> +++ b/sound/soc/qcom/qdsp6/q6apm-lpass-dais.c
> @@ -213,8 +213,10 @@ static int q6apm_lpass_dai_prepare(struct snd_pcm_substream *substream, struct s
>  
>  	return 0;
>  err:
> -	q6apm_graph_close(dai_data->graph[dai->id]);
> -	dai_data->graph[dai->id] = NULL;
> +	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
> +		q6apm_graph_close(dai_data->graph[dai->id]);
> +		dai_data->graph[dai->id] = NULL;
> +	}
>  	return rc;
>  }
>