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 234b7ca..ff01687 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);