[NETLINK]: don't reinitialize callback mutex

Don't reinitialize the callback mutex the netlink_kernel_create caller
handed in, it is supposed to already be initialized and could already
be held by someone.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 2 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index ec16c9b7b3bd..64d4b27f25ab 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -388,8 +388,12 @@ static int __netlink_create(struct socket *sock, struct mutex *cb_mutex,
         sock_init_data(sock, sk);
 
         nlk = nlk_sk(sk);
-        nlk->cb_mutex = cb_mutex ? : &nlk->cb_def_mutex;
-        mutex_init(nlk->cb_mutex);
+        if (cb_mutex)
+                nlk->cb_mutex = cb_mutex;
+        else {
+                nlk->cb_mutex = &nlk->cb_def_mutex;
+                mutex_init(nlk->cb_mutex);
+        }
         init_waitqueue_head(&nlk->wait);
 
         sk->sk_destruct = netlink_sock_destruct;