Re: [PATCH v3] usb: typec: anx7411: fix OF node reference leaks in anx7411_typec_switch_probe()

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

Hi,

Sorry to keep you waiting.

On Thu, Nov 21, 2024 at 11:39:14AM +0900, Joe Hattori wrote:
> The refcounts of the OF nodes obtained in by of_get_child_by_name()
> calls in anx7411_typec_switch_probe() are not decremented. Add
> additional device_node fields to anx7411_data, and call of_node_put() on
> them in the error path and in the unregister functions.
> 
> Fixes: e45d7337dc0e ("usb: typec: anx7411: Use of_get_child_by_name() instead of of_find_node_by_name()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
> ---
> Changes in v3:
> - Add new fields to anx7411_data.
> - Remove an unnecessary include.
> ---
>  drivers/usb/typec/anx7411.c | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/usb/typec/anx7411.c b/drivers/usb/typec/anx7411.c
> index 95607efb9f7e..e714b04399fa 100644
> --- a/drivers/usb/typec/anx7411.c
> +++ b/drivers/usb/typec/anx7411.c
> @@ -290,6 +290,8 @@ struct anx7411_data {
>  	struct power_supply *psy;
>  	struct power_supply_desc psy_desc;
>  	struct device *dev;
> +	struct device_node *switch_node;
> +	struct device_node *mux_node;

Please make these fwnodes.

>  };
>  
>  static u8 snk_identity[] = {
> @@ -1099,6 +1101,7 @@ static void anx7411_unregister_mux(struct anx7411_data *ctx)
>  	if (ctx->typec.typec_mux) {
>  		typec_mux_unregister(ctx->typec.typec_mux);
>  		ctx->typec.typec_mux = NULL;
> +		of_node_put(ctx->mux_node);

fwnode_handle_put(ctx->mux_node);

>  	}
>  }
>  
> @@ -1107,6 +1110,7 @@ static void anx7411_unregister_switch(struct anx7411_data *ctx)
>  	if (ctx->typec.typec_switch) {
>  		typec_switch_unregister(ctx->typec.typec_switch);
>  		ctx->typec.typec_switch = NULL;
> +		of_node_put(ctx->switch_node);

fwnode_handle_put(ctx->switch_node);

>  	}
>  }
>  
> @@ -1114,28 +1118,29 @@ static int anx7411_typec_switch_probe(struct anx7411_data *ctx,
>  				      struct device *dev)
>  {
>  	int ret;
> -	struct device_node *node;
>  
> -	node = of_get_child_by_name(dev->of_node, "orientation_switch");
> -	if (!node)
> +	ctx->switch_node = of_get_child_by_name(dev->of_node, "orientation_switch");

ctx->switch_node = device_get_named_child_node(dev, "orientation_switch");

> +	if (!ctx->switch_node)
>  		return 0;
>  
> -	ret = anx7411_register_switch(ctx, dev, &node->fwnode);
> +	ret = anx7411_register_switch(ctx, dev, &ctx->switch_node->fwnode);
>  	if (ret) {
>  		dev_err(dev, "failed register switch");
> +		of_node_put(ctx->switch_node);
>  		return ret;
>  	}
>  
> -	node = of_get_child_by_name(dev->of_node, "mode_switch");
> -	if (!node) {
> +	ctx->mux_node = of_get_child_by_name(dev->of_node, "mode_switch");

ctx->mux_node = device_get_named_child_node(dev, "mode_switch");

> +	if (!ctx->mux_node) {
>  		dev_err(dev, "no typec mux exist");
>  		ret = -ENODEV;
>  		goto unregister_switch;
>  	}
>  
> -	ret = anx7411_register_mux(ctx, dev, &node->fwnode);
> +	ret = anx7411_register_mux(ctx, dev, &ctx->mux_node->fwnode);
>  	if (ret) {
>  		dev_err(dev, "failed register mode switch");
> +		of_node_put(ctx->mux_node);
>  		ret = -ENODEV;
>  		goto unregister_switch;
>  	}

thanks,

-- 
heikki