netfilter: conntrack: skip identical origin tuple in same zone only

The origin skip check needs to re-test the zone. Else, we might skip
a colliding tuple in the reply direction.

This only occurs when using 'directional zones' where origin tuples
reside in different zones but the reply tuples share the same zone.

This causes the new conntrack entry to be dropped at confirmation time
because NAT clash resolution was elided.

Fixes: 4e35c1cb9460240 ("netfilter: nf_nat: skip nat clash resolution for same-origin entries")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 234b7cab37c301cd66025e43ffa5d9ce2e50ae47..ff0168736f6ea7309639bab9e73c0d72d7044203 100644 (file)
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1229,7 +1229,8 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
                         * Let nf_ct_resolve_clash() deal with this later.
                         */
                        if (nf_ct_tuple_equal(&ignored_conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
-                                             &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple))
+                                             &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple) &&
+                                             nf_ct_zone_equal(ct, zone, IP_CT_DIR_ORIGINAL))
                                continue;
 
                        NF_CT_STAT_INC_ATOMIC(net, found);