[PATCH net 1/9] mptcp: ensure subflow is unhashed before cleaning the backlog

From: Matthieu Baerts
Date: Tue Jul 04 2023 - 16:45:04 EST


From: Paolo Abeni <pabeni@xxxxxxxxxx>

While tacking care of the mptcp-level listener I unintentionally
moved the subflow level unhash after the subflow listener backlog
cleanup.

That could cause some nasty race and makes the code harder to read.

Address the issue restoring the proper order of operations.

Fixes: 57fc0f1ceaa4 ("mptcp: ensure listener is unhashed before updating the sk status")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
---
net/mptcp/protocol.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index e892673deb73..489a3defdde5 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2909,10 +2909,10 @@ static void mptcp_check_listen_stop(struct sock *sk)
return;

lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
+ tcp_set_state(ssk, TCP_CLOSE);
mptcp_subflow_queue_clean(sk, ssk);
inet_csk_listen_stop(ssk);
mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CLOSED);
- tcp_set_state(ssk, TCP_CLOSE);
release_sock(ssk);
}


--
2.40.1