[PATCH net 09/10] netfilter: flowtable: reset transport header after nf_flow_encap_pop()

[Pablo Neira Ayuso <pablo@netfilter.org>]

From: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>

nf_flow_encap_pop() pulls vlan/pppoe or ip tunnel headers and resets the
network header, but leaves the transport header pointing into the removed
outer header. Reset the transport header to the inner L4 header, otherwise
later consumers (e.g. GSO segmentation) parse a bogus header.

Fixes: 4cd91f7c290f ("netfilter: flowtable: add vlan support")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/nf_flow_table_ip.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 2dec15d402ca..bb894c4f2b4a 100644
--- a/net/netfilter/nf_flow_table_ip.c
+++ b/net/netfilter/nf_flow_table_ip.c
@@ -502,6 +502,7 @@ static int nf_flow_offload_forward(struct nf_flowtable_ctx *ctx,
 
 	nf_flow_encap_pop(ctx, skb, tuplehash);
 	thoff -= ctx->offset;
+	skb_set_transport_header(skb, thoff);
 
 	iph = ip_hdr(skb);
 	nf_flow_nat_ip(flow, skb, thoff, dir, iph);
@@ -1097,6 +1098,7 @@ static int nf_flow_offload_ipv6_forward(struct nf_flowtable_ctx *ctx,
 	flow_offload_refresh(flow_table, flow, false);
 
 	nf_flow_encap_pop(ctx, skb, tuplehash);
+	skb_set_transport_header(skb, sizeof(*ip6h));
 
 	ip6h = ipv6_hdr(skb);
 	nf_flow_nat_ipv6(flow, skb, dir, ip6h);
-- 
2.47.3