From e266ad04ec3993244b663303e3d2281524bb1732 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: 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 29849d77e4bf8..938cccab331dd 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2908,6 +2908,7 @@ bool __mptcp_close(struct sock *sk, long timeout) struct mptcp_subflow_context *subflow; struct mptcp_sock *msk = mptcp_sk(sk); bool do_cancel_work = false; + int subflows_alive = 0; sk->sk_shutdown = SHUTDOWN_MASK; @@ -2933,6 +2934,8 @@ bool __mptcp_close(struct sock *sk, long timeout) struct sock *ssk = mptcp_subflow_tcp_sock(subflow); bool slow = lock_sock_fast_nested(ssk); + subflows_alive += ssk->sk_state != TCP_CLOSE; + /* since the close timeout takes precedence on the fail one, * cancel the latter */ @@ -2948,6 +2951,12 @@ bool __mptcp_close(struct sock *sk, long timeout) } 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 (mptcp_sk(sk)->token)