Subject: Re: [PATCH 2/8] staging: wfx: check memory allocation

From: Kalle Valo <[email-masked]>
Date: Fri, 09 Oct 2020 21:51:01 +0300

Jerome Pouiller <[email-masked]> writes:

> From: Jérôme Pouiller <[email-masked]>
>
> Smatch complains:
>
>    main.c:228 wfx_send_pdata_pds() warn: potential NULL parameter dereference 'tmp_buf'
>    227          tmp_buf = kmemdup(pds->data, pds->size, GFP_KERNEL);
>    228          ret = wfx_send_pds(wdev, tmp_buf, pds->size);
>                                          ^^^^^^^
>    229          kfree(tmp_buf);
>
> Reported-by: Dan Carpenter <[email-masked]>
> Signed-off-by: Jérôme Pouiller <[email-masked]>
> ---
>  drivers/staging/wfx/main.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/wfx/main.c b/drivers/staging/wfx/main.c
> index df11c091e094..a8dc2c033410 100644
> --- a/drivers/staging/wfx/main.c
> +++ b/drivers/staging/wfx/main.c
> @@ -222,12 +222,18 @@ static int wfx_send_pdata_pds(struct wfx_dev *wdev)
>  	if (ret) {
>  		dev_err(wdev->dev, "can't load PDS file %s\n",
>  			wdev->pdata.file_pds);
> -		return ret;
> +		goto err1;
>  	}
>  	tmp_buf = kmemdup(pds->data, pds->size, GFP_KERNEL);
> +	if (!tmp_buf) {
> +		ret = -ENOMEM;
> +		goto err2;
> +	}
>  	ret = wfx_send_pds(wdev, tmp_buf, pds->size);
>  	kfree(tmp_buf);
> +err2:
>  	release_firmware(pds);
> +err1:
>  	return ret;
>  }

A minor style issue but using more descriptive error labels make the
code more readable and maintainable, especially in a bigger function.
For example, err2 could be called err_release_firmware.

And actually err1 could be removed and the goto replaced with just
"return ret;". Then err2 could be renamed to a simple err.

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