From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Klassert Subject: [PATCH 1/5] vti6: fix PMTU caching and reporting on xmit Date: Fri, 27 Jul 2018 08:51:50 +0200 Message-ID: <20180727065154.28557-2-steffen.klassert@secunet.com> References: <20180727065154.28557-1-steffen.klassert@secunet.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Herbert Xu , Steffen Klassert , To: David Miller Return-path: Received: from a.mx.secunet.com ([62.96.220.36]:55988 "EHLO a.mx.secunet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729489AbeG0IM0 (ORCPT ); Fri, 27 Jul 2018 04:12:26 -0400 In-Reply-To: <20180727065154.28557-1-steffen.klassert@secunet.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Eyal Birger 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: ccd740cbc6 ("vti6: Add pmtu handling to vti6_xmit.") Signed-off-by: Eyal Birger Signed-off-by: Steffen Klassert --- net/ipv6/ip6_vti.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c index b7f28deddaea..c72ae3a4fe09 100644 --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -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); -- 2.14.1