[PATCH 5.13 031/223] mptcp: remove redundant req destruct in subflow_check_req()

[Greg Kroah-Hartman]

From: Jianguo Wu <wujianguo@xxxxxxxxxxxxxxx>

[ Upstream commit 030d37bd1cd2443a1f21db47eb301899bfa45a2a ]

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@xxxxxxxxxxxxxxx>
Signed-off-by: Mat Martineau <mathew.j.martineau@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/mptcp/subflow.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index cbc452d0901e..5493c851ca6c 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -212,11 +212,6 @@ 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;
 			}
-- 
2.30.2