diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index eb142ca71fc5..86fbf0f3235e 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1078,9 +1078,12 @@ static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
 				int *copied, size_t size)
 {
 	struct tcp_sock *tp = tcp_sk(sk);
+	struct sockaddr *uaddr = msg->msg_name;
 	int err, flags;
 
-	if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE))
+	if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
+	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
+	     uaddr->sa_family == AF_UNSPEC))
 		return -EOPNOTSUPP;
 	if (tp->fastopen_req)
 		return -EALREADY; /* Another Fast Open is in progress */
@@ -1093,7 +1096,7 @@ static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
 	tp->fastopen_req->size = size;
 
 	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
-	err = __inet_stream_connect(sk->sk_socket, msg->msg_name,
+	err = __inet_stream_connect(sk->sk_socket, uaddr,
 				    msg->msg_namelen, flags);
 	*copied = tp->fastopen_req->copied;
 	tcp_free_fastopen_req(tp);