Re: [PATCH] staging: greybus: audio: Add missing unlock in gbaudio_dapm_free_controls()

[Johan Hovold]

On Fri, Dec 04, 2020 at 10:13:50AM +0800, Wang Hai wrote:
> Add the missing unlock before return from function
> gbaudio_dapm_free_controls() in the error handling case.
> 
> Fixes: 510e340efe0c ("staging: greybus: audio: Add helper APIs for dynamic audio module")
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
> ---
>  drivers/staging/greybus/audio_helper.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/staging/greybus/audio_helper.c b/drivers/staging/greybus/audio_helper.c
> index 237531ba60f3..293675dbea10 100644
> --- a/drivers/staging/greybus/audio_helper.c
> +++ b/drivers/staging/greybus/audio_helper.c
> @@ -135,6 +135,7 @@ int gbaudio_dapm_free_controls(struct snd_soc_dapm_context *dapm,
>  		if (!w) {
>  			dev_err(dapm->dev, "%s: widget not found\n",
>  				widget->name);
> +			mutex_unlock(&dapm->card->dapm_mutex);
>  			return -EINVAL;
>  		}
>  		widget++;

This superficially looks correct, but there seems to be another bug in
this function. It can be used free an array of widgets, but if one of
them isn't found we just leak the rest. Perhaps that return should
rather be "widget++; continue;".

Vaibhav?

Johan