diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index 8a2b0ae7dbd2bc..ab86036bbf0c28 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -209,7 +209,7 @@ extern struct nf_conntrack_tuple_hash *
 __nf_conntrack_find(struct net *net, u16 zone,
 		    const struct nf_conntrack_tuple *tuple);
 
-extern void nf_conntrack_hash_insert(struct nf_conn *ct);
+extern int nf_conntrack_hash_check_insert(struct nf_conn *ct);
 extern void nf_ct_delete_from_lists(struct nf_conn *ct);
 extern void nf_ct_insert_dying_list(struct nf_conn *ct);
 
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 76613f5a55c0c5..ed86a3be678ea2 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -404,19 +404,49 @@ static void __nf_conntrack_hash_insert(struct nf_conn *ct,
 			   &net->ct.hash[repl_hash]);
 }
 
-void nf_conntrack_hash_insert(struct nf_conn *ct)
+int
+nf_conntrack_hash_check_insert(struct nf_conn *ct)
 {
 	struct net *net = nf_ct_net(ct);
 	unsigned int hash, repl_hash;
+	struct nf_conntrack_tuple_hash *h;
+	struct hlist_nulls_node *n;
 	u16 zone;
 
 	zone = nf_ct_zone(ct);
-	hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
-	repl_hash = hash_conntrack(net, zone, &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+	hash = hash_conntrack(net, zone,
+			      &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+	repl_hash = hash_conntrack(net, zone,
+				   &ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+
+	spin_lock_bh(&nf_conntrack_lock);
 
+	/* 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_tuple_equal(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
+				      &h->tuple) &&
+		    zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
+			goto out;
+	hlist_nulls_for_each_entry(h, n, &net->ct.hash[repl_hash], hnnode)
+		if (nf_ct_tuple_equal(&ct->tuplehash[IP_CT_DIR_REPLY].tuple,
+				      &h->tuple) &&
+		    zone == nf_ct_zone(nf_ct_tuplehash_to_ctrack(h)))
+			goto out;
+
+	add_timer(&ct->timeout);
+	nf_conntrack_get(&ct->ct_general);
 	__nf_conntrack_hash_insert(ct, hash, repl_hash);
+	NF_CT_STAT_INC(net, insert);
+	spin_unlock_bh(&nf_conntrack_lock);
+
+	return 0;
+
+out:
+	NF_CT_STAT_INC(net, insert_failed);
+	spin_unlock_bh(&nf_conntrack_lock);
+	return -EEXIST;
 }
-EXPORT_SYMBOL_GPL(nf_conntrack_hash_insert);
+EXPORT_SYMBOL_GPL(nf_conntrack_hash_check_insert);
 
 /* Confirm a connection given skb; places it in hash table */
 int
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 9307b033c0c9d9..30c9d4ca02180e 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1367,15 +1367,12 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
 						    nf_ct_protonum(ct));
 		if (helper == NULL) {
 			rcu_read_unlock();
-			spin_unlock_bh(&nf_conntrack_lock);
 #ifdef CONFIG_MODULES
 			if (request_module("nfct-helper-%s", helpname) < 0) {
-				spin_lock_bh(&nf_conntrack_lock);
 				err = -EOPNOTSUPP;
 				goto err1;
 			}
 
-			spin_lock_bh(&nf_conntrack_lock);
 			rcu_read_lock();
 			helper = __nf_conntrack_helper_find(helpname,
 							    nf_ct_l3num(ct),
@@ -1468,8 +1465,10 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
 	if (tstamp)
 		tstamp->start = ktime_to_ns(ktime_get_real());
 
-	add_timer(&ct->timeout);
-	nf_conntrack_hash_insert(ct);
+	err = nf_conntrack_hash_check_insert(ct);
+	if (err < 0)
+		goto err2;
+
 	rcu_read_unlock();
 
 	return ct;
@@ -1490,6 +1489,7 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 	struct nf_conntrack_tuple otuple, rtuple;
 	struct nf_conntrack_tuple_hash *h = NULL;
 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
+	struct nf_conn *ct;
 	u_int8_t u3 = nfmsg->nfgen_family;
 	u16 zone;
 	int err;
@@ -1510,27 +1510,22 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 			return err;
 	}
 
-	spin_lock_bh(&nf_conntrack_lock);
 	if (cda[CTA_TUPLE_ORIG])
-		h = __nf_conntrack_find(net, zone, &otuple);
+		h = nf_conntrack_find_get(net, zone, &otuple);
 	else if (cda[CTA_TUPLE_REPLY])
-		h = __nf_conntrack_find(net, zone, &rtuple);
+		h = nf_conntrack_find_get(net, zone, &rtuple);
 
 	if (h == NULL) {
 		err = -ENOENT;
 		if (nlh->nlmsg_flags & NLM_F_CREATE) {
-			struct nf_conn *ct;
 			enum ip_conntrack_events events;
 
 			ct = ctnetlink_create_conntrack(net, zone, cda, &otuple,
 							&rtuple, u3);
-			if (IS_ERR(ct)) {
-				err = PTR_ERR(ct);
-				goto out_unlock;
-			}
+			if (IS_ERR(ct))
+				return PTR_ERR(ct);
+
 			err = 0;
-			nf_conntrack_get(&ct->ct_general);
-			spin_unlock_bh(&nf_conntrack_lock);
 			if (test_bit(IPS_EXPECTED_BIT, &ct->status))
 				events = IPCT_RELATED;
 			else
@@ -1545,23 +1540,19 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 						      ct, NETLINK_CB(skb).pid,
 						      nlmsg_report(nlh));
 			nf_ct_put(ct);
-		} else
-			spin_unlock_bh(&nf_conntrack_lock);
+		}
 
 		return err;
 	}
 	/* implicit 'else' */
 
-	/* We manipulate the conntrack inside the global conntrack table lock,
-	 * so there's no need to increase the refcount */
 	err = -EEXIST;
+	ct = nf_ct_tuplehash_to_ctrack(h);
 	if (!(nlh->nlmsg_flags & NLM_F_EXCL)) {
-		struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
-
+		spin_lock_bh(&nf_conntrack_lock);
 		err = ctnetlink_change_conntrack(ct, cda);
+		spin_unlock_bh(&nf_conntrack_lock);
 		if (err == 0) {
-			nf_conntrack_get(&ct->ct_general);
-			spin_unlock_bh(&nf_conntrack_lock);
 			nf_conntrack_eventmask_report((1 << IPCT_REPLY) |
 						      (1 << IPCT_ASSURED) |
 						      (1 << IPCT_HELPER) |
@@ -1570,15 +1561,10 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
 						      (1 << IPCT_MARK),
 						      ct, NETLINK_CB(skb).pid,
 						      nlmsg_report(nlh));
-			nf_ct_put(ct);
-		} else
-			spin_unlock_bh(&nf_conntrack_lock);
-
-		return err;
+		}
 	}
 
-out_unlock:
-	spin_unlock_bh(&nf_conntrack_lock);
+	nf_ct_put(ct);
 	return err;
 }