sctp: change sk state to CLOSED instead of CLOSING in sctp_sock_migrate

Commit d46e416c ("sctp: sctp should change socket state when
shutdown is received") may set sk_state CLOSING in sctp_sock_migrate,
but inet_accept doesn't allow the sk_state other than ESTABLISHED/
CLOSED for sctp. So we will change sk_state to CLOSED, instead of
CLOSING, as actually sk is closed already there.

Fixes: d46e416c ("sctp: sctp should change socket state when shutdown is received")
Reported-by: NYe Xiaolong <xiaolong.ye@intel.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/socket.c

@@ -7568,7 +7568,7 @@ static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
 	 * is called, set RCV_SHUTDOWN flag.
 	 */
 	if (sctp_state(assoc, CLOSED) && sctp_style(newsk, TCP)) {
-		newsk->sk_state = SCTP_SS_CLOSING;
+		newsk->sk_state = SCTP_SS_CLOSED;
 		newsk->sk_shutdown |= RCV_SHUTDOWN;
 	} else {
 		newsk->sk_state = SCTP_SS_ESTABLISHED;