[PATCH 2/4] mptcp: remove redundant req destruct in subflow_check_req()

[wujianguo106@163.com]

From: Jianguo Wu <wujianguo@chinatelecom.cn>

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>
---
 net/mptcp/subflow.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 6b1cd42..75ed530 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -213,11 +213,6 @@ static int subflow_check_req(struct request_sock *req,
 				 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;
 			}
-- 
1.8.3.1