RE: [PATCH net] ravb: Fix potential use-after-free in ravb_rx_gbeth()

[Biju Das]

Hi YueHaibing,

Thanks for the feedback.

> Subject: [PATCH net] ravb: Fix potential use-after-free in
> ravb_rx_gbeth()
> 
> The skb is delivered to napi_gro_receive() which may free it, after
> calling this, dereferencing skb may trigger use-after-free.

Can you please reconfirm the changes you have done is actually fixing any issue? 
If yes, please provide the details.

Current code,

napi_gro_receive(&priv->napi[q], priv->rx_1st_skb);

- stats->rx_bytes += priv->rx_1st_skb->len;
+ stats->rx_bytes += pkt_len;

Note: I haven't tested your patch yet to see it cause any regression.

Cheers,
Biju

> 
> Fixes: 1c59eb678cbd ("ravb: Fillup ravb_rx_gbeth() stub")
> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
> ---
>  drivers/net/ethernet/renesas/ravb_main.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> b/drivers/net/ethernet/renesas/ravb_main.c
> index 6bc923326268..33f723a9f471 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -841,7 +841,7 @@ static bool ravb_rx_gbeth(struct net_device *ndev,
> int *quota, int q)
>  				napi_gro_receive(&priv->napi[q],
>  						 priv->rx_1st_skb);
>  				stats->rx_packets++;
> -				stats->rx_bytes += priv->rx_1st_skb->len;
> +				stats->rx_bytes += pkt_len;
>  				break;
>  			}
>  		}
> --
> 2.34.1