Re: [PATCH net v2] net:thunderx:Fix resource leaks in device_for_each_child_node() loops

From: Benjamin Poirier
Date: Wed Jul 05 2023 - 15:29:26 EST


On 2023-07-05 22:34 +0800, Wang Ming wrote:
> The device_for_each_child_node() loop in
> bgx_init_of_phy() function should have
> wnode_handle_put() before break
^
fwnode_handle_put()

> which could avoid resource leaks.
> This patch could fix this bug.
>
> Signed-off-by: Wang Ming <machel@xxxxxxxx>
> ---
> drivers/net/ethernet/cavium/thunder/thunder_bgx.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
> index a317feb8decb..dad32d36a015 100644
> --- a/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
> +++ b/drivers/net/ethernet/cavium/thunder/thunder_bgx.c
> @@ -1478,8 +1478,10 @@ static int bgx_init_of_phy(struct bgx *bgx)
> * cannot handle it, so exit the loop.
> */
> node = to_of_node(fwn);
> - if (!node)
> + if (!node) {
> + fwnode_handle_put(fwn);
> break;
> + }

Fixes: eee326fd8334 ("net: thunderx: bgx: Use standard firmware node infrastructure.")
?

>
> of_get_mac_address(node, bgx->lmac[lmac].mac);
>
> @@ -1503,6 +1505,7 @@ static int bgx_init_of_phy(struct bgx *bgx)
> lmac++;
> if (lmac == bgx->max_lmac) {
> of_node_put(node);
> + fwnode_handle_put(fwn);

\ fwnode_handle_put
\ of_fwnode_put
of_node_put(to_of_node(fwnode));

With your patch, there are now two references released on 'node' (two
of_node_put(node) calls).
One reference is from device_for_each_child_node(), where was the other
reference taken?