Re: [PATCH v4 net-next 1/1] net_sched: Introduce skbmod action

[Eric Dumazet]

On Mon, 2016-09-12 at 16:46 -0400, Jamal Hadi Salim wrote:
> From: Jamal Hadi Salim <j...@mojatatu.com>

> +
> +     /* XXX: if you are going to edit more fields beyond ethernet header
> +      * (example when you add IP header replacement or vlan swap)
> +      * then MAX_EDIT_LEN needs to change appropriately
> +     */
> +     err = skb_ensure_writable(skb, ETH_HLEN);
> +     if (unlikely(err)) /* best policy is to drop on the floor */
> +             action = TC_ACT_SHOT;
> +
> +     rcu_read_lock();
> +     action = READ_ONCE(d->tcf_action);

You are overwriting @action, while you might have put TC_ACT_SHOT in it
3 lines above.

Maybe you meant :
        if (err)
                return TC_ACT_SHOT;