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Date:   Wed, 5 Jul 2023 15:29:19 -0400
From:   Benjamin Poirier <benjamin.poirier@gmail.com>
To:     Wang Ming <machel@vivo.com>
Cc:     Sunil Goutham <sgoutham@marvell.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        linux-arm-kernel@lists.infradead.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, opensource.kernel@vivo.com
Subject: Re: [PATCH net v2] net:thunderx:Fix resource leaks in
 device_for_each_child_node() loops
Message-ID: <ZKXEj6p/xkA+1yM4@d3>
References: <20230705143507.4120-1-machel@vivo.com>
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In-Reply-To: <20230705143507.4120-1-machel@vivo.com>
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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@vivo.com>
> ---
>  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?