From 3cfc5e84ac6fe3914304d4117589d113be2818f5 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 7 Feb 2023 14:04:13 +0100 Subject: [PATCH] mptcp: do not wait for bare sockets' timeout commit d4e85922e3e7ef2071f91f65e61629b60f3a9cf4 upstream. If the peer closes all the existing subflows for a given mptcp socket and later the application closes it, the current implementation let it survive until the timewait timeout expires. While the above is allowed by the protocol specification it consumes resources for almost no reason and additionally causes sporadic self-tests failures. Let's move the mptcp socket to the TCP_CLOSE state when there are no alive subflows at close time, so that the allocated resources will be freed immediately. Fixes: e16163b6e2b7 ("mptcp: refactor shutdown and close") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Matthieu Baerts Signed-off-by: Matthieu Baerts Signed-off-by: David S. Miller Signed-off-by: Matthieu Baerts Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 47f359dac247..5d05d85242bc 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2726,6 +2726,7 @@ static void mptcp_close(struct sock *sk, long timeout) { struct mptcp_subflow_context *subflow; bool do_cancel_work = false; + int subflows_alive = 0; lock_sock(sk); sk->sk_shutdown = SHUTDOWN_MASK; @@ -2747,11 +2748,19 @@ cleanup: struct sock *ssk = mptcp_subflow_tcp_sock(subflow); bool slow = lock_sock_fast_nested(ssk); + subflows_alive += ssk->sk_state != TCP_CLOSE; + sock_orphan(ssk); unlock_sock_fast(ssk, slow); } sock_orphan(sk); + /* all the subflows are closed, only timeout can change the msk + * state, let's not keep resources busy for no reasons + */ + if (subflows_alive == 0) + inet_sk_state_store(sk, TCP_CLOSE); + sock_hold(sk); pr_debug("msk=%p state=%d", sk, sk->sk_state); if (sk->sk_state == TCP_CLOSE) {