From 48e99107a3d7b8497a4f25cb40ea7bc521bf3330 Mon Sep 17 00:00:00 2001 From: Eyal Birger Date: Tue, 11 May 2021 17:16:58 +0800 Subject: [PATCH] xfrm: interface: fix ipv4 pmtu check to honor ip header df stable inclusion from linux-4.19.187 commit b318f319b0c81965adaba0997cdddd9e280270d5 -------------------------------- [ Upstream commit 8fc0e3b6a8666d656923d214e4dc791e9a17164a ] Frag needed should only be sent if the header enables DF. This fix allows packets larger than MTU to pass the xfrm interface and be fragmented after encapsulation, aligning behavior with non-interface xfrm. Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Signed-off-by: Eyal Birger Reviewed-by: Sabrina Dubroca Signed-off-by: Steffen Klassert Signed-off-by: Sasha Levin Signed-off-by: Yang Yingliang --- net/xfrm/xfrm_interface.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index 2e3fc48ced42..9dd43319b2c0 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -302,6 +302,8 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); } else { + if (!(ip_hdr(skb)->frag_off & htons(IP_DF))) + goto xmit; icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); } @@ -310,6 +312,7 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) return -EMSGSIZE; } +xmit: xfrmi_scrub_packet(skb, !net_eq(xi->net, dev_net(dev))); skb_dst_set(skb, dst); skb->dev = tdev; -- GitLab