[PATCH 4.19 24/48] seg6: fix skb checksum in SRv6 End.B6 and End.B6.Encaps behaviors

From: Greg Kroah-Hartman
Date: Tue Jul 19 2022 - 08:05:29 EST


From: Andrea Mayer <andrea.mayer@xxxxxxxxxxx>

[ Upstream commit f048880fc77058d864aff5c674af7918b30f312a ]

The SRv6 End.B6 and End.B6.Encaps behaviors rely on functions
seg6_do_srh_{encap,inline}() to, respectively: i) encapsulate the
packet within an outer IPv6 header with the specified Segment Routing
Header (SRH); ii) insert the specified SRH directly after the IPv6
header of the packet.

This patch removes the initialization of the IPv6 header payload length
from the input_action_end_b6{_encap}() functions, as it is now handled
properly by seg6_do_srh_{encap,inline}() to avoid corruption of the skb
checksum.

Fixes: 140f04c33bbc ("ipv6: sr: implement several seg6local actions")
Signed-off-by: Andrea Mayer <andrea.mayer@xxxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv6/seg6_local.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c
index 607709a8847c..18970f6a68c6 100644
--- a/net/ipv6/seg6_local.c
+++ b/net/ipv6/seg6_local.c
@@ -415,7 +415,6 @@ static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
if (err)
goto drop;

- ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_set_transport_header(skb, sizeof(struct ipv6hdr));

seg6_lookup_nexthop(skb, NULL, 0);
@@ -447,7 +446,6 @@ static int input_action_end_b6_encap(struct sk_buff *skb,
if (err)
goto drop;

- ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
skb_set_transport_header(skb, sizeof(struct ipv6hdr));

seg6_lookup_nexthop(skb, NULL, 0);
--
2.35.1