3 files changed, 15 insertions, 9 deletions

diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index 080f6ba..ab5d312 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h
@@ -187,6 +187,7 @@ extern struct sock *netlink_kernel_create(struct net *net,
 extern void netlink_kernel_release(struct sock *sk);
 extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);
 extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);
+extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);
 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
 extern int netlink_has_listeners(struct sock *sk, unsigned int group);
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 55180b9..a4bafbf 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1609,6 +1609,16 @@ int netlink_change_ngroups(struct sock *sk, unsigned int groups)
 	return err;
 }
 
+void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
+{
+	struct sock *sk;
+	struct hlist_node *node;
+	struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
+
+	sk_for_each_bound(sk, node, &tbl->mc_list)
+		netlink_update_socket_mc(nlk_sk(sk), group, 0);
+}
+
 /**
  * netlink_clear_multicast_users - kick off multicast listeners
  *
@@ -1619,15 +1629,8 @@ int netlink_change_ngroups(struct sock *sk, unsigned int groups)
  */
 void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
 {
-	struct sock *sk;
-	struct hlist_node *node;
-	struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
-
 	netlink_table_grab();
-
-	sk_for_each_bound(sk, node, &tbl->mc_list)
-		netlink_update_socket_mc(nlk_sk(sk), group, 0);
-
+	__netlink_clear_multicast_users(ksk, group);
 	netlink_table_ungrab();
 }
 
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 566941e..44ff3f3 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -220,10 +220,12 @@ static void __genl_unregister_mc_group(struct genl_family *family,
 	struct net *net;
 	BUG_ON(grp->family != family);
 
+	netlink_table_grab();
 	rcu_read_lock();
 	for_each_net_rcu(net)
-		netlink_clear_multicast_users(net->genl_sock, grp->id);
+		__netlink_clear_multicast_users(net->genl_sock, grp->id);
 	rcu_read_unlock();
+	netlink_table_ungrab();
 
 	clear_bit(grp->id, mc_groups);
 	list_del(&grp->list);