In subflow_check_req(), if subflow sport is mismatch, will put msk,
destroy token, and destruct req, then return -EPERM, which can be
done by subflow_req_destructor() via:
tcp_conn_request()
|--__reqsk_free()
|--subflow_req_destructor()
So we should remove these redundant code, otherwise will call
tcp_v4_reqsk_destructor() twice, and may double free
inet_rsk(req)->ireq_opt.
Fixes: 5bc56388c7 ("mptcp: add port number check for MP_JOIN")
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
030d37bd1c