gro: Check for GSO packets and packets with frag_list

As GRO cannot be applied to packets with frag_list we need to
make sure that we reject such packets if they are fed to us,
e.g., through a tunnel device.

Also there is no point in applying GRO on GSO packets so they
too should be rejected.  This allows GRO to be used in virtio-net
which may produce GSO packets directly but may still benefit
from GRO if the other end of it doesn't support GSO.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index b715a55cccc4..7dec715293b1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2392,6 +2392,9 @@ int dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
         if (!(skb->dev->features & NETIF_F_GRO))
                 goto normal;
 
+        if (skb_is_gso(skb) || skb_shinfo(skb)->frag_list)
+                goto normal;
+
         rcu_read_lock();
         list_for_each_entry_rcu(ptype, head, list) {
                 struct sk_buff *p;