Phonet: allow multiple listen() and fix small race condition

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 5 deletions

diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index 25f746d20c1f..ceb5143f5ef9 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -428,19 +428,19 @@ static int pn_socket_listen(struct socket *sock, int backlog)
         struct sock *sk = sock->sk;
         int err = 0;
 
-        if (sock->state != SS_UNCONNECTED)
-                return -EINVAL;
         if (pn_socket_autobind(sock))
                 return -ENOBUFS;
 
         lock_sock(sk);
-        if (sk->sk_state != TCP_CLOSE) {
+        if (sock->state != SS_UNCONNECTED) {
                 err = -EINVAL;
                 goto out;
         }
 
-        sk->sk_state = TCP_LISTEN;
-        sk->sk_ack_backlog = 0;
+        if (sk->sk_state != TCP_LISTEN) {
+                sk->sk_state = TCP_LISTEN;
+                sk->sk_ack_backlog = 0;
+        }
         sk->sk_max_ack_backlog = backlog;
 out:
         release_sock(sk);