From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2DD363B8 for ; Mon, 20 Feb 2023 13:53:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B8B2C4339B; Mon, 20 Feb 2023 13:53:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1676901189; bh=CKXPtMPsyjxt5m/mjliJGJhzn1rjocrOsDVJj7es5YE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jioy+IO1rOUmi7XFtYL90+sOGnnNtFv/cUWn6WuqTcbfaZobJHEjo3yM1IrOiAlci fMdxKA7CzPPpsssM6eHWqnRwntWacxRb9PJEWS1kcq9yOFwVQpInnB01+4W1GNQe56 coFisdYByyDjEXz3Yo0KG8cOqJlwmciSrrh7zSPs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Abeni , Matthieu Baerts , "David S. Miller" Subject: [PATCH 5.15 34/83] mptcp: do not wait for bare sockets timeout Date: Mon, 20 Feb 2023 14:36:07 +0100 Message-Id: <20230220133554.844189134@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230220133553.669025851@linuxfoundation.org> References: <20230220133553.669025851@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Paolo Abeni 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(+) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2726,6 +2726,7 @@ static void mptcp_close(struct sock *sk, { 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) {