Commit e80ad525 authored by Victor Nogueira's avatar Victor Nogueira Committed by Paolo Abeni
Browse files

net/sched: act_mirred: Fix return code in early mirred redirect error paths 



Since retval is set as TC_ACT_STOLEN in the mirred redirect case, returning
retval in cases where redirect failed will make the callers not register
the skb as being dropped.

Fix this by returning TC_ACT_SHOT instead in such scenarios.

Fixes: 16085e48 ("net/sched: act_mirred: Create function tcf_mirred_to_dev and improve readability")
Reported-by: default avatarSashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260413082027.2244884-1-hxzene%40gmail.com


Signed-off-by: default avatarVictor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20260525122556.973584-8-jhs@mojatatu.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent a005fa5d

net/sched/act_mirred.c

+13 −5
Original line number Diff line number Diff line
@@ -372,7 +372,8 @@ static int tcf_blockcast_redir(struct sk_buff *skb, struct tcf_mirred *m, 
					 dev_is_mac_header_xmit(dev_prev),

					 m_eaction, retval);



	return retval;

	/* If the packet wasn't redirected, we have to register as a drop */

	return TC_ACT_SHOT;

}



static int tcf_blockcast_mirror(struct sk_buff *skb, struct tcf_mirred *m,
@@ -410,7 +411,7 @@ static int tcf_blockcast(struct sk_buff *skb, struct tcf_mirred *m, 
	block = tcf_block_lookup(dev_net(skb->dev), blockid);

	if (!block || xa_empty(&block->ports)) {

		tcf_action_inc_overlimit_qstats(&m->common);

		return retval;

		return is_redirect ? TC_ACT_SHOT : retval;

	}



	if (is_redirect)
@@ -428,8 +429,8 @@ TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, 
{

	struct tcf_mirred *m = to_mirred(a);

	int retval = READ_ONCE(m->tcf_action);

	bool m_mac_header_xmit, is_redirect;

	struct netdev_xmit *xmit;

	bool m_mac_header_xmit;

	struct net_device *dev;

	bool want_ingress;

	int i, m_eaction;
@@ -462,11 +463,13 @@ TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, 
		return retval;

	}



	is_redirect = tcf_mirred_is_act_redirect(m_eaction);



	dev = rcu_dereference_bh(m->tcfm_dev);

	if (unlikely(!dev)) {

		pr_notice_once("tc mirred: target device is gone\n");

		tcf_action_inc_overlimit_qstats(&m->common);

		return retval;

		goto err_out;

	}



	if (!want_ingress) {
@@ -476,7 +479,7 @@ TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, 
			pr_notice_once("tc mirred: loop on device %s\n",

				       netdev_name(dev));

			tcf_action_inc_overlimit_qstats(&m->common);

			return retval;

			goto err_out;

		}

		xmit->sched_mirred_dev[xmit->sched_mirred_nest++] = dev;

	}
@@ -489,6 +492,11 @@ TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, 
		xmit->sched_mirred_nest--;



	return retval;



err_out:

	if (is_redirect)

		retval = TC_ACT_SHOT;

	return retval;

}



static void tcf_stats_update(struct tc_action *a, u64 bytes, u64 packets,