1 files changed, 44 insertions, 28 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 3c56b96b4a4b..444ed223ee43 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -102,6 +102,7 @@ struct netlink_table {
         struct hlist_head mc_list;
         unsigned int nl_nonroot;
         struct module *module;
+        int registered;
 };
 
 static struct netlink_table *nl_table;
@@ -343,11 +344,32 @@ static struct proto netlink_proto = {
         .obj_size = sizeof(struct netlink_sock),
 };
 
-static int netlink_create(struct socket *sock, int protocol)
+static int __netlink_create(struct socket *sock, int protocol)
 {
         struct sock *sk;
         struct netlink_sock *nlk;
-        struct module *module;
+
+        sock->ops = &netlink_ops;
+
+        sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
+        if (!sk)
+                return -ENOMEM;
+
+        sock_init_data(sock, sk);
+
+        nlk = nlk_sk(sk);
+        spin_lock_init(&nlk->cb_lock);
+        init_waitqueue_head(&nlk->wait);
+
+        sk->sk_destruct = netlink_sock_destruct;
+        sk->sk_protocol = protocol;
+        return 0;
+}
+
+static int netlink_create(struct socket *sock, int protocol)
+{
+        struct module *module = NULL;
+        int err = 0;
 
         sock->state = SS_UNCONNECTED;
 
@@ -358,41 +380,33 @@ static int netlink_create(struct socket *sock, int protocol)
                 return -EPROTONOSUPPORT;
 
         netlink_lock_table();
-        if (!nl_table[protocol].hash.entries) {
 #ifdef CONFIG_KMOD
-                /* We do 'best effort'.  If we find a matching module,
-                 * it is loaded.  If not, we don't return an error to
-                 * allow pure userspace<->userspace communication. -HW
-                 */
+        if (!nl_table[protocol].registered) {
                 netlink_unlock_table();
                 request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
                 netlink_lock_table();
-#endif
         }
-        module = nl_table[protocol].module;
-        if (!try_module_get(module))
-                module = NULL;
+#endif
+        if (nl_table[protocol].registered &&
+            try_module_get(nl_table[protocol].module))
+                module = nl_table[protocol].module;
+        else
+                err = -EPROTONOSUPPORT;
         netlink_unlock_table();
 
-        sock->ops = &netlink_ops;
-
-        sk = sk_alloc(PF_NETLINK, GFP_KERNEL, &netlink_proto, 1);
-        if (!sk) {
-                module_put(module);
-                return -ENOMEM;
-        }
-
-        sock_init_data(sock, sk);
+        if (err)
+                goto out;
 
-        nlk = nlk_sk(sk);
+        if ((err = __netlink_create(sock, protocol) < 0))
+                goto out_module;
 
-        nlk->module = module;
-        spin_lock_init(&nlk->cb_lock);
-        init_waitqueue_head(&nlk->wait);
-        sk->sk_destruct = netlink_sock_destruct;
+        nlk_sk(sock->sk)->module = module;
+out:
+        return err;
 
-        sk->sk_protocol = protocol;
-        return 0;
+out_module:
+        module_put(module);
+        goto out;
 }
 
 static int netlink_release(struct socket *sock)
@@ -437,6 +451,7 @@ static int netlink_release(struct socket *sock)
         if (nlk->flags & NETLINK_KERNEL_SOCKET) {
                 netlink_table_grab();
                 nl_table[sk->sk_protocol].module = NULL;
+                nl_table[sk->sk_protocol].registered = 0;
                 netlink_table_ungrab();
         }
 
@@ -1082,7 +1097,7 @@ netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct
         if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
                 return NULL;
 
-        if (netlink_create(sock, unit) < 0)
+        if (__netlink_create(sock, unit) < 0)
                 goto out_sock_release;
 
         sk = sock->sk;
@@ -1098,6 +1113,7 @@ netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len), struct
 
         netlink_table_grab();
         nl_table[unit].module = module;
+        nl_table[unit].registered = 1;
         netlink_table_ungrab();
 
         return sk;