mptcp: remove redundant req destruct in subflow_check_req()

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: 5bc56388c74f ("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>

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 66d0b18..b15e201 100644 (file)
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -214,11 +214,6 @@ again:
                                 ntohs(inet_sk(sk_listener)->inet_sport),
                                 ntohs(inet_sk((struct sock *)subflow_req->msk)->inet_sport));
                        if (!mptcp_pm_sport_in_anno_list(subflow_req->msk, sk_listener)) {
-                               sock_put((struct sock *)subflow_req->msk);
-                               mptcp_token_destroy_request(req);
-                               tcp_request_sock_ops.destructor(req);
-                               subflow_req->msk = NULL;
-                               subflow_req->mp_join = 0;
                                SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTSYNRX);
                                return -EPERM;
                        }