vti6: fix PMTU caching and reporting on xmit (d6990976) · Commits · 戴 / test

When setting the skb->dst before doing the MTU check, the route PMTU caching and reporting is done on the new dst which is about to be released. Instead, PMTU handling should be done using the original dst. This is aligned with IPv4 VTI. Fixes: ("vti6: Add pmtu handling to vti6_xmit.") Signed-off-by:

Eyal Birger <eyal.birger@gmail.com> Signed-off-by:

Steffen Klassert <steffen.klassert@secunet.com>

net/ipv6/ip6_vti.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -480,10 +480,6 @@ vti6_xmit(struct sk_buff skb, struct net_device dev, struct flowi *fl)
		goto tx_err_dst_release;
		}

		skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
		skb_dst_set(skb, dst);
		skb->dev = skb_dst(skb)->dev;

		mtu = dst_mtu(dst);
		if (!skb->ignore_df && skb->len > mtu) {
		skb_dst_update_pmtu(skb, mtu);
		@@ -498,9 +494,14 @@ vti6_xmit(struct sk_buff skb, struct net_device dev, struct flowi *fl)
		htonl(mtu));
		}

		return -EMSGSIZE;
		err = -EMSGSIZE;
		goto tx_err_dst_release;
		}

		skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
		skb_dst_set(skb, dst);
		skb->dev = skb_dst(skb)->dev;

		err = dst_output(t->net, skb->sk, skb);
		if (net_xmit_eval(err) == 0) {
		struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);

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