gro: Fix handling of complete checksums in IPv6

We need to perform skb_postpull_rcsum after pulling the IPv6
header in order to maintain the correctness of the complete
checksum.

This patch also adds a missing iph reload after pulling.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 0 deletions

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 94f74f5b0cbf..c802bc1658a8 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -797,6 +797,7 @@ static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
         unsigned int nlen;
         int flush = 1;
         int proto;
+        __wsum csum;
 
         if (unlikely(!pskb_may_pull(skb, sizeof(*iph))))
                 goto out;
@@ -808,6 +809,7 @@ static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
 
         rcu_read_lock();
         proto = ipv6_gso_pull_exthdrs(skb, iph->nexthdr);
+        iph = ipv6_hdr(skb);
         IPV6_GRO_CB(skb)->proto = proto;
         ops = rcu_dereference(inet6_protos[proto]);
         if (!ops || !ops->gro_receive)
@@ -839,8 +841,13 @@ static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
 
         NAPI_GRO_CB(skb)->flush |= flush;
 
+        csum = skb->csum;
+        skb_postpull_rcsum(skb, iph, skb_network_header_len(skb));
+
         pp = ops->gro_receive(head, skb);
 
+        skb->csum = csum;
+
 out_unlock:
         rcu_read_unlock();