Re: [PATCH net] net: ethernet: rtsn: fix potential memory leak in rtsn_start_xmit()

[Eric Dumazet]

On Mon, Oct 14, 2024 at 4:43 PM Wang Hai <wanghai38@xxxxxxxxxx> wrote:
>
> The rtsn_start_xmit() returns NETDEV_TX_OK without freeing skb
> in case of skb->len being too long, add dev_kfree_skb_any() to fix it.
>
> Fixes: b0d3969d2b4d ("net: ethernet: rtsn: Add support for Renesas Ethernet-TSN")
> Signed-off-by: Wang Hai <wanghai38@xxxxxxxxxx>
> ---
>  drivers/net/ethernet/renesas/rtsn.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/ethernet/renesas/rtsn.c b/drivers/net/ethernet/renesas/rtsn.c
> index f9f63c61d792..6b3f7fca8d15 100644
> --- a/drivers/net/ethernet/renesas/rtsn.c
> +++ b/drivers/net/ethernet/renesas/rtsn.c
> @@ -1057,6 +1057,7 @@ static netdev_tx_t rtsn_start_xmit(struct sk_buff *skb, struct net_device *ndev)
>         if (skb->len >= TX_DS) {
>                 priv->stats.tx_dropped++;
>                 priv->stats.tx_errors++;
> +               dev_kfree_skb_any(skb);
>                 goto out;
>         }
>

Note this is dead code for this driver. This condition should never be
hit with checks in upper layers,
because TX_DS is bigger than device max mtu.

Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>