Re: [PATCH] ASoC: SOF: icp3-dtrace: Fix wrong kfree() usage

[Péter Ujfalusi <peter.ujfalusi@xxxxxxxxxxxxxxx>]

On 17/11/2023 00:01, Kamil Duljas wrote:
> trace_filter_parse() allocs memory for *out and when
> -ENOMEM is returned, caller function, dfsentry_trace_filter_write()
> trying to freed this memory.
> 
> After this patch, the memory is freed in trace_filter_parse()
> before -EINVAL returned. In caller function removed kfree(elms)
> from error label

I think the original code was cleaner:
the elems is always freed up in dfsentry_trace_filter_write() in one place.
kfree(NULL); is not an error, it is handled correctly

> 
> Signed-off-by: Kamil Duljas <kamil.duljas@xxxxxxxxx>
> ---
>  sound/soc/sof/ipc3-dtrace.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/soc/sof/ipc3-dtrace.c b/sound/soc/sof/ipc3-dtrace.c
> index 0dca139322f3..93b189c2d2ee 100644
> --- a/sound/soc/sof/ipc3-dtrace.c
> +++ b/sound/soc/sof/ipc3-dtrace.c
> @@ -137,6 +137,7 @@ static int trace_filter_parse(struct snd_sof_dev *sdev, char *string,
>  			dev_err(sdev->dev,
>  				"Parsing filter entry '%s' failed with %d\n",
>  				entry, entry_len);
> +			kfree(*out);
>  			return -EINVAL;
>  		}
>  	}
> @@ -208,13 +209,13 @@ static ssize_t dfsentry_trace_filter_write(struct file *file, const char __user
>  		ret = ipc3_trace_update_filter(sdev, num_elems, elems);
>  		if (ret < 0) {
>  			dev_err(sdev->dev, "Filter update failed: %d\n", ret);
> +			kfree(elems);
>  			goto error;
>  		}
>  	}
>  	ret = count;
>  error:
>  	kfree(string);
> -	kfree(elems);
>  	return ret;
>  }
>  

-- 
Péter