[PATCH 5.19 213/717] esp: choose the correct inner protocol for GSO on inter address family tunnels

Greg Kroah-Hartman
2022-10-22T07:47:46Z

From: Sabrina Dubroca <sd@queasysnail.net>

[ Upstream commit 26dbd66eab8080be51759e48280da04015221e22 ]

Commit 23c7f8d7989e ("net: Fix esp GSO on inter address family
tunnels.") is incomplete. It passes to skb_eth_gso_segment the
protocol for the outer IP version, instead of the inner IP version, so
we end up calling inet_gso_segment on an inner IPv6 packet and
ipv6_gso_segment on an inner IPv4 packet and the packets are dropped.

This patch completes the fix by selecting the correct protocol based
on the inner mode's family.

Fixes: c35fe4106b92 ("xfrm: Add mode handlers for IPsec on layer 2")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/esp4_offload.c | 5 ++++-
net/ipv6/esp6_offload.c | 5 ++++-
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c
index 935026f4c807..170152772d33 100644
--- a/net/ipv4/esp4_offload.c
+++ b/net/ipv4/esp4_offload.c
@@ -110,7 +110,10 @@ static struct sk_buff *xfrm4_tunnel_gso_segment(struct xfrm_state *x,
struct sk_buff *skb,
netdev_features_t features)
{
- return skb_eth_gso_segment(skb, features, htons(ETH_P_IP));
+ __be16 type = x->inner_mode.family == AF_INET6 ? htons(ETH_P_IPV6)
+ : htons(ETH_P_IP);
+
+ return skb_eth_gso_segment(skb, features, type);
}

static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x,
diff --git a/net/ipv6/esp6_offload.c b/net/ipv6/esp6_offload.c
index 3a293838a91d..79d43548279c 100644
--- a/net/ipv6/esp6_offload.c
+++ b/net/ipv6/esp6_offload.c
@@ -145,7 +145,10 @@ static struct sk_buff *xfrm6_tunnel_gso_segment(struct xfrm_state *x,
struct sk_buff *skb,
netdev_features_t features)
{
- return skb_eth_gso_segment(skb, features, htons(ETH_P_IPV6));
+ __be16 type = x->inner_mode.family == AF_INET ? htons(ETH_P_IP)
+ : htons(ETH_P_IPV6);
+
+ return skb_eth_gso_segment(skb, features, type);
}

static struct sk_buff *xfrm6_transport_gso_segment(struct xfrm_state *x,
--
2.35.1