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

[ Upstream commit 07998281c268592963e1cd623fe6ab0270b65ae4 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index ad1da6b2fb607c46edd6a05bccdac5e762ccd712..1dceda3c0e75961ac9dfd752cf90ff0889de9aba 100644 (file)
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1063,7 +1063,8 @@ 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);