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>

diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index c25068e385169b3aee21594df68446696756ad91..5a449b44ba33255f4acebc28879a37ae7e3ab3bd 100644 (file)
--- 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;
 }