[PATCH] ASoC: xilinx: formatter_pcm: fix stream_data leak on open error

[PATCH] ASoC: xilinx: formatter_pcm: fix stream_data leak on open error

[Rosen Penev]

In xlnx_formatter_pcm_open(), stream_data is allocated and
adata->play_stream or adata->capture_stream is assigned early.  If a
later step, such as snd_pcm_hw_constraint_step() or
snd_pcm_hw_constraint_integer(), fails, the function returns the error
immediately.  ALSA does not call the close callback when open fails, so
stream_data is leaked and the stream pointer is left dangling, pointing
to a substream that ALSA frees.  A later interrupt would then call
snd_pcm_period_elapsed() on the freed substream.

Free stream_data and clear the stream pointer on the error paths.

Fixes: 6f6c3c36f091 ("ASoC: xlnx: add pcm formatter platform driver")
Assisted-by: opencode:deepseek-v4-flash-free
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 sound/soc/xilinx/xlnx_formatter_pcm.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/sound/soc/xilinx/xlnx_formatter_pcm.c b/sound/soc/xilinx/xlnx_formatter_pcm.c
index 7eba3a0205f1..4f4c1e650aaf 100644
--- a/sound/soc/xilinx/xlnx_formatter_pcm.c
+++ b/sound/soc/xilinx/xlnx_formatter_pcm.c
@@ -385,7 +385,7 @@ static int xlnx_formatter_pcm_open(struct snd_soc_component *component,
 	if (err) {
 		dev_err(component->dev,
 			"Unable to set constraint on period bytes\n");
-		return err;
+		goto err;
 	}
 
 	/* Resize the buffer bytes as divisible by 64 */
@@ -395,7 +395,7 @@ static int xlnx_formatter_pcm_open(struct snd_soc_component *component,
 	if (err) {
 		dev_err(component->dev,
 			"Unable to set constraint on buffer bytes\n");
-		return err;
+		goto err;
 	}
 
 	/* Set periods as integer multiple */
@@ -404,7 +404,7 @@ static int xlnx_formatter_pcm_open(struct snd_soc_component *component,
 	if (err < 0) {
 		dev_err(component->dev,
 			"Unable to set constraint on periods to be integer\n");
-		return err;
+		goto err;
 	}
 
 	/* enable DMA IOC irq */
@@ -413,6 +413,14 @@ static int xlnx_formatter_pcm_open(struct snd_soc_component *component,
 	writel(val, stream_data->mmio + XLNX_AUD_CTRL);
 
 	return 0;
+
+err:
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		adata->play_stream = NULL;
+	else
+		adata->capture_stream = NULL;
+	kfree(stream_data);
+	return err;
 }
 
 static int xlnx_formatter_pcm_close(struct snd_soc_component *component,
-- 
2.55.0

Re: [PATCH] ASoC: xilinx: formatter_pcm: fix stream_data leak on open error

[Michal Simek]

On 8/7/26 02:40, Rosen Penev wrote:
> In xlnx_formatter_pcm_open(), stream_data is allocated and
> adata->play_stream or adata->capture_stream is assigned early.  If a
> later step, such as snd_pcm_hw_constraint_step() or
> snd_pcm_hw_constraint_integer(), fails, the function returns the error
> immediately.  ALSA does not call the close callback when open fails, so
> stream_data is leaked and the stream pointer is left dangling, pointing
> to a substream that ALSA frees.  A later interrupt would then call
> snd_pcm_period_elapsed() on the freed substream.
> 
> Free stream_data and clear the stream pointer on the error paths.
> 
> Fixes: 6f6c3c36f091 ("ASoC: xlnx: add pcm formatter platform driver")
> Assisted-by: opencode:deepseek-v4-flash-free
> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
>   sound/soc/xilinx/xlnx_formatter_pcm.c | 14 +++++++++++---
>   1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/sound/soc/xilinx/xlnx_formatter_pcm.c b/sound/soc/xilinx/xlnx_formatter_pcm.c
> index 7eba3a0205f1..4f4c1e650aaf 100644
> --- a/sound/soc/xilinx/xlnx_formatter_pcm.c
> +++ b/sound/soc/xilinx/xlnx_formatter_pcm.c
> @@ -385,7 +385,7 @@ static int xlnx_formatter_pcm_open(struct snd_soc_component *component,
>   	if (err) {
>   		dev_err(component->dev,
>   			"Unable to set constraint on period bytes\n");
> -		return err;
> +		goto err;
>   	}
>   
>   	/* Resize the buffer bytes as divisible by 64 */
> @@ -395,7 +395,7 @@ static int xlnx_formatter_pcm_open(struct snd_soc_component *component,
>   	if (err) {
>   		dev_err(component->dev,
>   			"Unable to set constraint on buffer bytes\n");
> -		return err;
> +		goto err;
>   	}
>   
>   	/* Set periods as integer multiple */
> @@ -404,7 +404,7 @@ static int xlnx_formatter_pcm_open(struct snd_soc_component *component,
>   	if (err < 0) {
>   		dev_err(component->dev,
>   			"Unable to set constraint on periods to be integer\n");
> -		return err;
> +		goto err;
>   	}
>   
>   	/* enable DMA IOC irq */
> @@ -413,6 +413,14 @@ static int xlnx_formatter_pcm_open(struct snd_soc_component *component,
>   	writel(val, stream_data->mmio + XLNX_AUD_CTRL);
>   
>   	return 0;
> +
> +err:

err is also variable in this code that's why I suggest you to rename this label.

> +	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
> +		adata->play_stream = NULL;
> +	else
> +		adata->capture_stream = NULL;
> +	kfree(stream_data);
> +	return err;
>   }
>   
>   static int xlnx_formatter_pcm_close(struct snd_soc_component *component,

With that fixed fell free to add

Reviewed-by: Michal Simek <michal.simek@amd.com>

Thanks,
Michal