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=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 53C6AC2B9F4 for ; Mon, 14 Jun 2021 10:40:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3540E613DC for ; Mon, 14 Jun 2021 10:40:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233912AbhFNKmO (ORCPT ); Mon, 14 Jun 2021 06:42:14 -0400 Received: from mail.kernel.org ([198.145.29.99]:45350 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234094AbhFNKkB (ORCPT ); Mon, 14 Jun 2021 06:40:01 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id BB5946141C; Mon, 14 Jun 2021 10:34:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623666878; bh=SOUGqBQp3nV7DuXkoujlT2Q0GjI1fUhgMLBbG88LWCo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1rCIyUUC1aZNlUPt/R8uBrTGSTwlZeHl0miktFa7O3KDJmW5cvY1VqvRGDDUpPNNe x57kzfuXqhi/I0ZEP22fuOPFdCXZbvxIPq+Xpzza2k/Wovqp6ob49y9iX7xM8mNSHK h/kTVS+22mSeKv/O2r3qH3/RzEEbV6lXZIZB0OIc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Rao Shoaib , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 14/67] RDS tcp loopback connection can hang Date: Mon, 14 Jun 2021 12:26:57 +0200 Message-Id: <20210614102644.258076824@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210614102643.797691914@linuxfoundation.org> References: <20210614102643.797691914@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Rao Shoaib [ Upstream commit aced3ce57cd37b5ca332bcacd370d01f5a8c5371 ] When TCP is used as transport and a program on the system connects to RDS port 16385, connection is accepted but denied per the rules of RDS. However, RDS connections object is left in the list. Next loopback connection will select that connection object as it is at the head of list. The connection attempt will hang as the connection object is set to connect over TCP which is not allowed The issue can be reproduced easily, use rds-ping to ping a local IP address. After that use any program like ncat to connect to the same IP address and port 16385. This will hang so ctrl-c out. Now try rds-ping, it will hang. To fix the issue this patch adds checks to disallow the connection object creation and destroys the connection object. Signed-off-by: Rao Shoaib Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/rds/connection.c | 23 +++++++++++++++++------ net/rds/tcp.c | 4 ++-- net/rds/tcp.h | 3 ++- net/rds/tcp_listen.c | 6 ++++++ 4 files changed, 27 insertions(+), 9 deletions(-) diff --git a/net/rds/connection.c b/net/rds/connection.c index 3bd2f4a5a30d..ac3300b204a6 100644 --- a/net/rds/connection.c +++ b/net/rds/connection.c @@ -237,12 +237,23 @@ static struct rds_connection *__rds_conn_create(struct net *net, if (loop_trans) { rds_trans_put(loop_trans); conn->c_loopback = 1; - if (is_outgoing && trans->t_prefer_loopback) { - /* "outgoing" connection - and the transport - * says it wants the connection handled by the - * loopback transport. This is what TCP does. - */ - trans = &rds_loop_transport; + if (trans->t_prefer_loopback) { + if (likely(is_outgoing)) { + /* "outgoing" connection to local address. + * Protocol says it wants the connection + * handled by the loopback transport. + * This is what TCP does. + */ + trans = &rds_loop_transport; + } else { + /* No transport currently in use + * should end up here, but if it + * does, reset/destroy the connection. + */ + kmem_cache_free(rds_conn_slab, conn); + conn = ERR_PTR(-EOPNOTSUPP); + goto out; + } } } diff --git a/net/rds/tcp.c b/net/rds/tcp.c index 18bb522df282..d0bce439198f 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -322,8 +322,8 @@ out: } #endif -static int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr, - __u32 scope_id) +int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr, + __u32 scope_id) { struct net_device *dev = NULL; #if IS_ENABLED(CONFIG_IPV6) diff --git a/net/rds/tcp.h b/net/rds/tcp.h index 3c69361d21c7..4620549ecbeb 100644 --- a/net/rds/tcp.h +++ b/net/rds/tcp.h @@ -60,7 +60,8 @@ u32 rds_tcp_snd_una(struct rds_tcp_connection *tc); u64 rds_tcp_map_seq(struct rds_tcp_connection *tc, u32 seq); extern struct rds_transport rds_tcp_transport; void rds_tcp_accept_work(struct sock *sk); - +int rds_tcp_laddr_check(struct net *net, const struct in6_addr *addr, + __u32 scope_id); /* tcp_connect.c */ int rds_tcp_conn_path_connect(struct rds_conn_path *cp); void rds_tcp_conn_path_shutdown(struct rds_conn_path *conn); diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c index c12203f646da..0d095d3f5fee 100644 --- a/net/rds/tcp_listen.c +++ b/net/rds/tcp_listen.c @@ -198,6 +198,12 @@ int rds_tcp_accept_one(struct socket *sock) } #endif + if (!rds_tcp_laddr_check(sock_net(sock->sk), peer_addr, dev_if)) { + /* local address connection is only allowed via loopback */ + ret = -EOPNOTSUPP; + goto out; + } + conn = rds_conn_create(sock_net(sock->sk), my_addr, peer_addr, &rds_tcp_transport, GFP_KERNEL, dev_if); -- 2.30.2