netfilter: ctnetlink: be more strict when NF_CONNTRACK_MARK is not set

When CONFIG_NF_CONNTRACK_MARK is not set, any CTA_MARK or CTA_MARK_MASK
in netlink message are not supported. We should return an error when one
of them is set, not both

Fixes: 9306425b ("netfilter: ctnetlink: must check mark attributes vs NULL")
Signed-off-by: Romain Bellan <romain.bellan@wifirst.fr>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_conntrack_netlink.c

@@ -860,7 +860,7 @@ ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
 	struct ctnetlink_filter *filter;
 
 #ifndef CONFIG_NF_CONNTRACK_MARK
-	if (cda[CTA_MARK] && cda[CTA_MARK_MASK])
+	if (cda[CTA_MARK] || cda[CTA_MARK_MASK])
 		return ERR_PTR(-EOPNOTSUPP);
 #endif