netfilter: conntrack: don't deliver events for racy packets

This patch skips the delivery of conntrack events if the packet
was drop due to a race condition in the conntrack insertion.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index c25068e38516..5a449b44ba33 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -62,7 +62,8 @@ static inline int nf_conntrack_confirm(struct sk_buff *skb)
         if (ct && ct != &nf_conntrack_untracked) {
                 if (!nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct))
                         ret = __nf_conntrack_confirm(skb);
-                nf_ct_deliver_cached_events(ct);
+                if (likely(ret == NF_ACCEPT))
+                        nf_ct_deliver_cached_events(ct);
         }
         return ret;
 }