Re: [PATCH] ASoC: intel: Fix memleak in sst_media_open

[Pierre-Louis Bossart]

On 8/9/20 3:56 AM, Dinghao Liu wrote:
> When power_up_sst() fails, stream needs to be freed
> just like when try_module_get() fails. However, current
> code is returning directly and ends up leaking memory.
>
> Fixes: 0121327c1a68b ("ASoC: Intel: mfld-pcm: add control for powering up/down dsp")
> Signed-off-by: Dinghao Liu <dinghao.liu@xxxxxxxxxx>
> ---
>   sound/soc/intel/atom/sst-mfld-platform-pcm.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/sound/soc/intel/atom/sst-mfld-platform-pcm.c b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
> index 49b9f18472bc..79fedf9e3da1 100644
> --- a/sound/soc/intel/atom/sst-mfld-platform-pcm.c
> +++ b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
> @@ -330,8 +330,10 @@ static int sst_media_open(struct snd_pcm_substream *substream,
>   	runtime->private_data = stream;
>   
>   	ret_val = power_up_sst(stream);
> -	if (ret_val < 0)
> +	if (ret_val < 0) {
> +		kfree(stream);
>   		return ret_val;
> +	}
>   
>   	/* Make sure, that the period size is always even */
>   	snd_pcm_hw_constraint_step(substream->runtime, 0,

Alternate suggestion to fix this, it's not great when we mix gotos and 
returns.

diff --git a/sound/soc/intel/atom/sst-mfld-platform-pcm.c 
b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
index 49b9f18472bc..b1cac7abdc0a 100644
--- a/sound/soc/intel/atom/sst-mfld-platform-pcm.c
+++ b/sound/soc/intel/atom/sst-mfld-platform-pcm.c
@@ -331,7 +331,7 @@ static int sst_media_open(struct snd_pcm_substream 
*substream,

        ret_val = power_up_sst(stream);
        if (ret_val < 0)
-               return ret_val;
+               goto out_power_up;

        /* Make sure, that the period size is always even */
        snd_pcm_hw_constraint_step(substream->runtime, 0,
@@ -340,8 +340,9 @@ static int sst_media_open(struct snd_pcm_substream 
*substream,
        return snd_pcm_hw_constraint_integer(runtime,
                         SNDRV_PCM_HW_PARAM_PERIODS);
 out_ops:
-       kfree(stream);
        mutex_unlock(&sst_lock);
+out_power_up:
+       kfree(stream);
        return ret_val;
 }