1 files changed, 40 insertions, 4 deletions

diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 3e797d1..a265033 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -39,6 +39,15 @@ static char __initdata nfversion[] = "0.30";
 static const struct nfnetlink_subsystem __rcu *subsys_table[NFNL_SUBSYS_COUNT];
 static DEFINE_MUTEX(nfnl_mutex);
 
+static const int nfnl_group2type[NFNLGRP_MAX+1] = {
+	[NFNLGRP_CONNTRACK_NEW]		= NFNL_SUBSYS_CTNETLINK,
+	[NFNLGRP_CONNTRACK_UPDATE]	= NFNL_SUBSYS_CTNETLINK,
+	[NFNLGRP_CONNTRACK_DESTROY]	= NFNL_SUBSYS_CTNETLINK,
+	[NFNLGRP_CONNTRACK_EXP_NEW]	= NFNL_SUBSYS_CTNETLINK_EXP,
+	[NFNLGRP_CONNTRACK_EXP_UPDATE]	= NFNL_SUBSYS_CTNETLINK_EXP,
+	[NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP,
+};
+
 void nfnl_lock(void)
 {
 	mutex_lock(&nfnl_mutex);
@@ -169,8 +178,10 @@ replay:
 
 		err = nla_parse(cda, ss->cb[cb_id].attr_count,
 				attr, attrlen, ss->cb[cb_id].policy);
-		if (err < 0)
+		if (err < 0) {
+			rcu_read_unlock();
 			return err;
+		}
 
 		if (nc->call_rcu) {
 			err = nc->call_rcu(net->nfnl, skb, nlh,
@@ -184,9 +195,11 @@ replay:
 					lockdep_is_held(&nfnl_mutex)) != ss ||
 			    nfnetlink_find_client(type, ss) != nc)
 				err = -EAGAIN;
-			else
+			else if (nc->call)
 				err = nc->call(net->nfnl, skb, nlh,
 						   (const struct nlattr **)cda);
+			else
+				err = -EINVAL;
 			nfnl_unlock();
 		}
 		if (err == -EAGAIN)
@@ -200,12 +213,35 @@ static void nfnetlink_rcv(struct sk_buff *skb)
 	netlink_rcv_skb(skb, &nfnetlink_rcv_msg);
 }
 
+#ifdef CONFIG_MODULES
+static void nfnetlink_bind(int group)
+{
+	const struct nfnetlink_subsystem *ss;
+	int type = nfnl_group2type[group];
+
+	rcu_read_lock();
+	ss = nfnetlink_get_subsys(type);
+	if (!ss) {
+		rcu_read_unlock();
+		request_module("nfnetlink-subsys-%d", type);
+		return;
+	}
+	rcu_read_unlock();
+}
+#endif
+
 static int __net_init nfnetlink_net_init(struct net *net)
 {
 	struct sock *nfnl;
+	struct netlink_kernel_cfg cfg = {
+		.groups	= NFNLGRP_MAX,
+		.input	= nfnetlink_rcv,
+#ifdef CONFIG_MODULES
+		.bind	= nfnetlink_bind,
+#endif
+	};
 
-	nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, NFNLGRP_MAX,
-				     nfnetlink_rcv, NULL, THIS_MODULE);
+	nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, THIS_MODULE, &cfg);
 	if (!nfnl)
 		return -ENOMEM;
 	net->nfnl_stash = nfnl;