net: Discard and warn about LRO'd skbs received for forwarding

Add skb_warn_if_lro() to test whether an skb was received with LRO and
warn if so.

Change br_forward(), ip_forward() and ip6_forward() to call it) and
discard the skb if it returns true.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 40a2813a63d1..fd7cd1bfe151 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -407,6 +407,9 @@ int ip6_forward(struct sk_buff *skb)
         if (ipv6_devconf.forwarding == 0)
                 goto error;
 
+        if (skb_warn_if_lro(skb))
+                goto drop;
+
         if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) {
                 IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_INDISCARDS);
                 goto drop;