Subject: Re: [PATCH net] net: stmmac: selftests: fix potential memleak in stmmac_test_arpoffload()

From: Leon Romanovsky <[email-masked]>
Date: Wed, 7 Dec 2022 11:12:25 +0200

On Wed, Dec 07, 2022 at 04:31:59PM +0800, Zhang Changzhong wrote:
> The skb allocated by stmmac_test_get_arp_skb() hasn't been released in
> some error handling case, which will lead to a memory leak. Fix this up
> by adding kfree_skb() to release skb.
> 
> Compile tested only.
> 
> Fixes: 5e3fb0a6e2b3 ("net: stmmac: selftests: Implement the ARP Offload test")
> Signed-off-by: Zhang Changzhong <[email-masked]>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> index 49af7e7..687f43c 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> @@ -1654,12 +1654,16 @@ static int stmmac_test_arpoffload(struct stmmac_priv *priv)
>  	}
>  
>  	ret = stmmac_set_arp_offload(priv, priv->hw, true, ip_addr);
> -	if (ret)
> +	if (ret) {
> +		kfree_skb(skb);
>  		goto cleanup;
> +	}
>  
>  	ret = dev_set_promiscuity(priv->dev, 1);
> -	if (ret)
> +	if (ret) {
> +		kfree_skb(skb);
>  		goto cleanup;
> +	}
>  
>  	ret = dev_direct_xmit(skb, 0);
>  	if (ret)

You should release skb here too. So the better patch will be to write
something like that:

cleanup:
  stmmac_set_arp_offload(priv, priv->hw, false, 0x0);
  if (ret)
  	kfree_skb(skb);

Thanks

> -- 
> 2.9.5