[NET]: Verify gso_type too in gso_segment

We don't want nasty Xen guests to pass a TCPv6 packet in with gso_type set
to TCPv4 or even UDP (or a packet that's both TCP and UDP).

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

1 files changed, 8 insertions, 0 deletions

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index c28e5c287447..ec59344478d2 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -64,6 +64,14 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, int features)
         struct inet6_protocol *ops;
         int proto;
 
+        if (unlikely(skb_shinfo(skb)->gso_type &
+                     ~(SKB_GSO_UDP |
+                       SKB_GSO_DODGY |
+                       SKB_GSO_TCP_ECN |
+                       SKB_GSO_TCPV6 |
+                       0)))
+                goto out;
+
         if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
                 goto out;