Re: [PATCH] backlight: qcom-wled: Add NULL check in the wled_configure

[Daniel Thompson]

On Mon, Mar 31, 2025 at 05:12:45PM +0800, Henry Martin wrote:
> When devm_kasprintf() fails, it returns a NULL pointer. However, this return value is not properly checked in the function wled_configure.
>
> A NULL check should be added after the devm_kasprintf call to prevent potential NULL pointer dereference error.
>
> Fixes: f86b77583d88c ("backlight: pm8941: Convert to using %pOFn instead of device_node.name")
>
> Signed-off-by: Henry Martin <bsdhenrymartin@xxxxxxxxx>
> ---
>  drivers/video/backlight/qcom-wled.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 9afe701b2a1b..db5eda8ec37e 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -1406,8 +1406,14 @@ static int wled_configure(struct wled *wled)
>  	wled->ctrl_addr = be32_to_cpu(*prop_addr);
>
>  	rc = of_property_read_string(dev->of_node, "label", &wled->name);
> -	if (rc)
> +	if (rc) {
>  		wled->name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
> +		if (!wled->name) {
> +			dev_err(dev, "Failed to allocate memory for wled name\n");
> +			return -ENOMEM;
> +		}
> +	}
> +

No objections to the check but I don't think it needs a dev_err(). It
is a waste of .text to store a string that is likely never to be
printed.


Daniel.