netfilter: conntrack: check netns when comparing conntrack objects

Once we place all conntracks in the same hash table we must also compare
the netns pointer to skip conntracks that belong to a different namespace.

Signed-off-by: Florian Westphal <[e-mail]>
Signed-off-by: Pablo Neira Ayuso <[e-mail]>

net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c

···
 #endif
 
 static bool ct_seq_should_skip(const struct nf_conn *ct,
+			       const struct net *net,
 			       const struct nf_conntrack_tuple_hash *hash)
 {
 	/* we only want to print DIR_ORIGINAL */
···
 		return true;
 
 	if (nf_ct_l3num(ct) != AF_INET)
+		return true;
+
+	if (!net_eq(nf_ct_net(ct), net))
 		return true;
 
 	return false;
···
 	int ret = 0;
 
 	NF_CT_ASSERT(ct);
-	if (ct_seq_should_skip(ct, hash))
+	if (ct_seq_should_skip(ct, seq_file_net(s), hash))
 		return 0;
 
 	if (unlikely(!atomic_inc_not_zero(&ct->ct_general.use)))
···
 
 	/* check if we raced w. object reuse */
 	if (!nf_ct_is_confirmed(ct) ||
-	    ct_seq_should_skip(ct, hash))
+	    ct_seq_should_skip(ct, seq_file_net(s), hash))
 		goto release;
 
 	l3proto = __nf_ct_l3proto_find(nf_ct_l3num(ct));

net/netfilter/nf_conntrack_core.c

···
 static inline bool
 nf_ct_key_equal(struct nf_conntrack_tuple_hash *h,
 		const struct nf_conntrack_tuple *tuple,
-		const struct nf_conntrack_zone *zone)
+		const struct nf_conntrack_zone *zone,
+		const struct net *net)
 {
 	struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
 
···
 	 */
 	return nf_ct_tuple_equal(tuple, &h->tuple) &&
 	       nf_ct_zone_equal(ct, zone, NF_CT_DIRECTION(h)) &&
-	       nf_ct_is_confirmed(ct);
+	       nf_ct_is_confirmed(ct) &&
+	       net_eq(net, nf_ct_net(ct));
 }
 
 /*
···
 	} while (read_seqcount_retry(&nf_conntrack_generation, sequence));
 
 	hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[bucket], hnnode) {
-		if (nf_ct_key_equal(h, tuple, zone)) {
+		if (nf_ct_key_equal(h, tuple, zone, net)) {
 			NF_CT_STAT_INC_ATOMIC(net, found);
 			return h;
 		}
···
 			     !atomic_inc_not_zero(&ct->ct_general.use)))
 			h = NULL;
 		else {
-			if (unlikely(!nf_ct_key_equal(h, tuple, zone))) {
+			if (unlikely(!nf_ct_key_equal(h, tuple, zone, net))) {
 				nf_ct_put(ct);
 				goto begin;
 			}
···
 	/* See if there's one in the list already, including reverse */
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 		if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
-				    zone))
+				    zone, net))
 			goto out;
 
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 		if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
-				    zone))
+				    zone, net))
 			goto out;
 
 	add_timer(&ct->timeout);
···
 	   not in the hash.  If there is, we lost race. */
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[hash], hnnode)
 		if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
-				    zone))
+				    zone, net))
 			goto out;
 
 	hlist_nulls_for_each_entry(h, n, &net->ct.hash[reply_hash], hnnode)
 		if (nf_ct_key_equal(h, &ct->tuplehash[IP_CT_DIR_REPLY].tuple,
-				    zone))
+				    zone, net))
 			goto out;
 
 	/* Timer relative to confirmation time, not original
···
 	hlist_nulls_for_each_entry_rcu(h, n, &ct_hash[hash], hnnode) {
 		ct = nf_ct_tuplehash_to_ctrack(h);
 		if (ct != ignored_conntrack &&
-		    nf_ct_key_equal(h, tuple, zone)) {
+		    nf_ct_key_equal(h, tuple, zone, net)) {
 			NF_CT_STAT_INC_ATOMIC(net, found);
 			rcu_read_unlock();
 			return 1;
···
 				if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
 					continue;
 				ct = nf_ct_tuplehash_to_ctrack(h);
-				if (iter(ct, data))
+				if (net_eq(nf_ct_net(ct), net) &&
+				    iter(ct, data))
 					goto found;
 			}
 		}

net/netfilter/nf_conntrack_netlink.c

···
 			if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
 				continue;
 			ct = nf_ct_tuplehash_to_ctrack(h);
+			if (!net_eq(net, nf_ct_net(ct)))
+				continue;
+
 			/* Dump entries of a given L3 protocol number.
 			 * If it is not specified, ie. l3proto == 0,
 			 * then dump everything. */