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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Sabrina Dubroca <sd@queasysnail.net>,
        Steffen Klassert <steffen.klassert@secunet.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.19 213/717] esp: choose the correct inner protocol for GSO on inter address family tunnels
Date:   Sat, 22 Oct 2022 09:21:32 +0200
Message-Id: <20221022072452.962173379@linuxfoundation.org>
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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