From 7ad49c28b62381d2f8cbd9957c09962e36ad25bc Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 21 Jun 2021 18:52:54 -0700 Subject: [PATCH] ip6_tunnel: fix GRE6 segmentation Commit 348f50a0faea ("ip6_tunnel: add MPLS transmit support") moved assiging inner_ipproto down from ipxip6_tnl_xmit() to its callee ip6_tnl_xmit(). The latter is also used by GRE. Since commit acb97fea7f8e ("gre: Use inner_proto to obtain inner header protocol") GRE had been depending on skb->inner_protocol during segmentation. It sets it in gre_build_header() and reads it in gre_gso_segment(). Changes to ip6_tnl_xmit() overwrite the protocol, resulting in GSO skbs getting dropped. Note that inner_protocol is a union with inner_ipproto, GRE uses the former while the change switched it to the latter (always setting it to just IPPROTO_GRE). Restore the original location of skb_set_inner_ipproto(), it is unclear why it was moved in the first place. Fixes: 348f50a0faea ("ip6_tunnel: add MPLS transmit support") Signed-off-by: Jakub Kicinski Tested-by: Vadim Fedorenko Signed-off-by: David S. Miller --- net/ipv6/ip6_tunnel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 288bafded9989..28ca70af014ad 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1239,8 +1239,6 @@ route_lookup: if (max_headroom > dev->needed_headroom) dev->needed_headroom = max_headroom; - skb_set_inner_ipproto(skb, proto); - err = ip6_tnl_encap(skb, t, &proto, fl6); if (err) return err; @@ -1377,6 +1375,8 @@ ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6)) return -1; + skb_set_inner_ipproto(skb, protocol); + err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, protocol); if (err != 0) { -- 2.39.5