6.6-stable review patch. If anyone has any objections, please let me know.
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From: Sabrina Dubroca sd@queasysnail.net
[ Upstream commit 1118aaa3b35157777890fffab91d8c1da841b20b ]
Commit b40c5f4fde22 ("udp: disable inner UDP checksum offloads in IPsec case") tried to fix checksumming in UFO when the packets are going through IPsec, so that we can't rely on offloads because the UDP header and payload will be encrypted.
But when doing a TCP test over VXLAN going through IPsec transport mode with GSO enabled (esp4_offload module loaded), I'm seeing broken UDP checksums on the encap after successful decryption.
The skbs get to udp4_ufo_fragment/__skb_udp_tunnel_segment via __dev_queue_xmit -> validate_xmit_skb -> skb_gso_segment and at this point we've already dropped the dst (unless the device sets IFF_XMIT_DST_RELEASE, which is not common), so need_ipsec is false and we proceed with checksum offload.
Make need_ipsec also check the secpath, which is not dropped on this callpath.
Fixes: b40c5f4fde22 ("udp: disable inner UDP checksum offloads in IPsec case") 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/udp_offload.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c index 3870b59f5400..9be9df2caf65 100644 --- a/net/ipv4/udp_offload.c +++ b/net/ipv4/udp_offload.c @@ -61,7 +61,7 @@ static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb, remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM); skb->remcsum_offload = remcsum;
- need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb)); + need_ipsec = (skb_dst(skb) && dst_xfrm(skb_dst(skb))) || skb_sec_path(skb); /* Try to offload checksum if possible */ offload_csum = !!(need_csum && !need_ipsec &&