From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A4BCC433E0 for ; Mon, 29 Jun 2020 20:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7EE320656 for ; Mon, 29 Jun 2020 20:27:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VFjSfibb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389112AbgF2U1H (ORCPT ); Mon, 29 Jun 2020 16:27:07 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:23314 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2389108AbgF2U1E (ORCPT ); Mon, 29 Jun 2020 16:27:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593462422; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XceIh8Y3sIXxWbc3XYUgBoKNPJ4S9xUkoJ2RIbjdXC8=; b=VFjSfibbHCcOkXdDIKruetCQGGN3D/XbrGshn8pX+jo5LVzTl55iSbrAUwEoyKEGlnYjV9 SIkztJkuvVa3/rLOPJkDdQZcWO9AvaRfBIiT5BYy+7+ujvf2GbR/KxtI01ndPFp66g8Qvp /bbiOgZA349S1kFszQLR8cKH5i2E9J4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-106-rUUopEosOeG89pBzx5nmMw-1; Mon, 29 Jun 2020 16:26:57 -0400 X-MC-Unique: rUUopEosOeG89pBzx5nmMw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 66A951932487; Mon, 29 Jun 2020 20:26:56 +0000 (UTC) Received: from new-host-5.redhat.com (unknown [10.40.194.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id CDA831C4; Mon, 29 Jun 2020 20:26:54 +0000 (UTC) From: Davide Caratti To: Mat Martineau , Matthieu Baerts , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, mptcp@lists.01.org Subject: [PATCH net-next 6/6] mptcp: close poll() races Date: Mon, 29 Jun 2020 22:26:25 +0200 Message-Id: <0c0e9026c97b90d92047b3771dc248e5d873ac6a.1593461586.git.dcaratti@redhat.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Paolo Abeni mptcp_poll always return POLLOUT for unblocking connect(), ensure that the socket is a suitable state. The MPTCP_DATA_READY bit is never cleared on accept: ensure we don't leave mptcp_accept() with an empty accept queue and such bit set. Signed-off-by: Paolo Abeni Signed-off-by: Davide Caratti --- net/mptcp/protocol.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index f2b2bd37e371..28ec26d97f96 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1841,6 +1841,7 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, if (!ssock) goto unlock_fail; + clear_bit(MPTCP_DATA_READY, &msk->flags); sock_hold(ssock->sk); release_sock(sock->sk); @@ -1861,6 +1862,8 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, } } + if (inet_csk_listen_poll(ssock->sk)) + set_bit(MPTCP_DATA_READY, &msk->flags); sock_put(ssock->sk); return err; @@ -1869,21 +1872,33 @@ static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, return -EINVAL; } +static __poll_t mptcp_check_readable(struct mptcp_sock *msk) +{ + return test_bit(MPTCP_DATA_READY, &msk->flags) ? EPOLLIN | EPOLLRDNORM : + 0; +} + static __poll_t mptcp_poll(struct file *file, struct socket *sock, struct poll_table_struct *wait) { struct sock *sk = sock->sk; struct mptcp_sock *msk; __poll_t mask = 0; + int state; msk = mptcp_sk(sk); sock_poll_wait(file, sock, wait); - if (test_bit(MPTCP_DATA_READY, &msk->flags)) - mask = EPOLLIN | EPOLLRDNORM; - if (sk_stream_is_writeable(sk) && - test_bit(MPTCP_SEND_SPACE, &msk->flags)) - mask |= EPOLLOUT | EPOLLWRNORM; + state = inet_sk_state_load(sk); + if (state == TCP_LISTEN) + return mptcp_check_readable(msk); + + if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) { + mask |= mptcp_check_readable(msk); + if (sk_stream_is_writeable(sk) && + test_bit(MPTCP_SEND_SPACE, &msk->flags)) + mask |= EPOLLOUT | EPOLLWRNORM; + } if (sk->sk_shutdown & RCV_SHUTDOWN) mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; -- 2.26.2