From: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Date: Wed, 13 Sep 2017 19:30:51 -0600
Subject: udpv6: Fix the checksum computation when HW checksum does not apply
Patch-mainline: v4.14-rc2
Git-commit: 63ecc3d9436f8012e49dc846d6cb0a85a3433517
References: bsc#1076830

While trying an ESP transport mode encryption for UDPv6 packets of
datagram size 1436 with MTU 1500, checksum error was observed in
the secondary fragment.

This error occurs due to the UDP payload checksum being missed out
when computing the full checksum for these packets in
udp6_hwcsum_outgoing().

Fixes: d39d938c8228 ("ipv6: Introduce udpv6_send_skb()")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Kubecek <mkubecek@suse.cz>

---
 net/ipv6/udp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index cf5f5bd1742c..f722d9fedb44 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -996,6 +996,7 @@ static void udp6_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
 		 */
 		offset = skb_transport_offset(skb);
 		skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);
+		csum = skb->csum;
 
 		skb->ip_summed = CHECKSUM_NONE;
 
-- 
2.15.1