Re: [PATCH v2] net: ethernet: renesas: rswitch: fix device_node refcount leak in rswitch_get_port_node()

On Sat, Aug 15, 2026 at 12:34:23AM +0530, manushprajwal wrote:
> From: Manush Prajwal <[email protected]>
> 
> On an of_property_read_u32() failure, rswitch_get_port_node() set port
> to NULL and jumped to the out label before releasing the reference the
> for_each_available_child_of_node() iterator was holding on it. Once
> port was overwritten with NULL, that reference could never be
> released since out: only put "ports", the parent node.
> 
> Rework the function around for_each_available_child_of_node_scoped()
> instead of adding a manual of_node_put(), so the iterator's reference
> is dropped automatically on every exit path. Since port is the
> function's return value, take an explicit reference with of_node_get()
> on the match before breaking out of the loop.
> 
> Signed-off-by: Manush Prajwal <[email protected]>
> ---
> v2: Rework using for_each_available_child_of_node_scoped() instead of
>     a manual of_node_put(), per Andrew Lunn's review.
> 
>  drivers/net/ethernet/renesas/rswitch_main.c | 20 +++++++++-----------
>  1 file changed, 9 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/ethernet/renesas/rswitch_main.c b/drivers/net/ethernet/renesas/rswitch_main.c
> index 6fe9648163..ffdc42f430 100644
> --- a/drivers/net/ethernet/renesas/rswitch_main.c
> +++ b/drivers/net/ethernet/renesas/rswitch_main.c
> @@ -1303,8 +1303,8 @@
>  /* Call of_node_put(port) after done */
>  static struct device_node *rswitch_get_port_node(struct rswitch_device *rdev)
>  {
> -	struct device_node *ports, *port;
> -	int err = 0;
> +	struct device_node *ports;
> +	struct device_node *port = NULL;
>  	u32 index;

Reverse Christmas tree.

    Andrew

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