Re: [PATCH 3/3] thermal: of: Fix OF node leak in of_thermal_zone_find() error paths

[Chen-Yu Tsai]

On Wed, Aug 14, 2024 at 09:58:23PM +0200, Krzysztof Kozlowski wrote:
> Terminating for_each_available_child_of_node() loop requires dropping OF
> node reference, so bailing out on errors misses this.  Solve the OF node
> reference leak with scoped for_each_available_child_of_node_scoped().
> 
> Fixes: 3fd6d6e2b4e8 ("thermal/of: Rework the thermal device tree initialization")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>

Reviewed-by: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>

> ---
>  drivers/thermal/thermal_of.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
> index b08a9b64718d..1f252692815a 100644
> --- a/drivers/thermal/thermal_of.c
> +++ b/drivers/thermal/thermal_of.c
> @@ -184,14 +184,14 @@ static struct device_node *of_thermal_zone_find(struct device_node *sensor, int
>  	 * Search for each thermal zone, a defined sensor
>  	 * corresponding to the one passed as parameter
>  	 */
> -	for_each_available_child_of_node(np, tz) {
> +	for_each_available_child_of_node_scoped(np, child) {
>  
>  		int count, i;
>  
> -		count = of_count_phandle_with_args(tz, "thermal-sensors",
> +		count = of_count_phandle_with_args(child, "thermal-sensors",
>  						   "#thermal-sensor-cells");
>  		if (count <= 0) {
> -			pr_err("%pOFn: missing thermal sensor\n", tz);
> +			pr_err("%pOFn: missing thermal sensor\n", child);
>  			tz = ERR_PTR(-EINVAL);
>  			goto out;
>  		}
> @@ -200,18 +200,19 @@ static struct device_node *of_thermal_zone_find(struct device_node *sensor, int
>  
>  			int ret;
>  
> -			ret = of_parse_phandle_with_args(tz, "thermal-sensors",
> +			ret = of_parse_phandle_with_args(child, "thermal-sensors",
>  							 "#thermal-sensor-cells",
>  							 i, &sensor_specs);
>  			if (ret < 0) {
> -				pr_err("%pOFn: Failed to read thermal-sensors cells: %d\n", tz, ret);
> +				pr_err("%pOFn: Failed to read thermal-sensors cells: %d\n", child, ret);
>  				tz = ERR_PTR(ret);
>  				goto out;
>  			}
>  
>  			if ((sensor == sensor_specs.np) && id == (sensor_specs.args_count ?
>  								  sensor_specs.args[0] : 0)) {
> -				pr_debug("sensor %pOFn id=%d belongs to %pOFn\n", sensor, id, tz);
> +				pr_debug("sensor %pOFn id=%d belongs to %pOFn\n", sensor, id, child);
> +				tz = no_free_ptr(child);
>  				goto out;
>  			}
>  		}
> -- 
> 2.43.0
>