2 files changed, 27 insertions, 2 deletions

diff --git a/net/ipv4/netfilter/ip_nat_rule.c b/net/ipv4/netfilter/ip_nat_rule.c
index 60d70fa41a15..cb66b8bddeb3 100644
--- a/net/ipv4/netfilter/ip_nat_rule.c
+++ b/net/ipv4/netfilter/ip_nat_rule.c
@@ -255,6 +255,27 @@ alloc_null_binding(struct ip_conntrack *conntrack,
         return ip_nat_setup_info(conntrack, &range, hooknum);
 }
 
+unsigned int
+alloc_null_binding_confirmed(struct ip_conntrack *conntrack,
+                             struct ip_nat_info *info,
+                             unsigned int hooknum)
+{
+        u_int32_t ip
+                = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
+                   ? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip
+                   : conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip);
+        u_int16_t all
+                = (HOOK2MANIP(hooknum) == IP_NAT_MANIP_SRC
+                   ? conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.all
+                   : conntrack->tuplehash[IP_CT_DIR_REPLY].tuple.src.u.all);
+        struct ip_nat_range range
+                = { IP_NAT_RANGE_MAP_IPS, ip, ip, { all }, { all } };
+
+        DEBUGP("Allocating NULL binding for confirmed %p (%u.%u.%u.%u)\n",
+               conntrack, NIPQUAD(ip));
+        return ip_nat_setup_info(conntrack, &range, hooknum);
+}
+
 int ip_nat_rule_find(struct sk_buff **pskb,
                      unsigned int hooknum,
                      const struct net_device *in,
diff --git a/net/ipv4/netfilter/ip_nat_standalone.c b/net/ipv4/netfilter/ip_nat_standalone.c
index 89db052add81..0ff368b131f6 100644
--- a/net/ipv4/netfilter/ip_nat_standalone.c
+++ b/net/ipv4/netfilter/ip_nat_standalone.c
@@ -123,8 +123,12 @@ ip_nat_fn(unsigned int hooknum,
                 if (!ip_nat_initialized(ct, maniptype)) {
                         unsigned int ret;
 
-                        /* LOCAL_IN hook doesn't have a chain!  */
-                        if (hooknum == NF_IP_LOCAL_IN)
+                        if (unlikely(is_confirmed(ct)))
+                                /* NAT module was loaded late */
+                                ret = alloc_null_binding_confirmed(ct, info,
+                                                                   hooknum);
+                        else if (hooknum == NF_IP_LOCAL_IN)
+                                /* LOCAL_IN hook doesn't have a chain!  */
                                 ret = alloc_null_binding(ct, info, hooknum);
                         else
                                 ret = ip_nat_rule_find(pskb, hooknum,