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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 F14ECC433DF for ; Tue, 26 May 2020 18:55:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C88B2208C3 for ; Tue, 26 May 2020 18:55:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519359; bh=NOUY2cFAxW4NOpv/x7vgV6FUGdxcy+oqZ/7YtptmUIs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MD8DESH08SoTPKfdEl8E6BSMdTII9g7tHDGVOBmBeOm04XjE+lORkwtpEjWgrSDh6 6sH4dtAwgrLtG+MUrJe+dUlDZ98D7Rrcl2ruf3/0T7ZLWxZFcFXpFyLHvWUTuvnj7L fJFBIZK6nB4HWOM4U0TmoLsGmp+5eOXcmZ0UQ0co= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389684AbgEZSz5 (ORCPT ); Tue, 26 May 2020 14:55:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:48382 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389671AbgEZSzx (ORCPT ); Tue, 26 May 2020 14:55:53 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 830232086A; Tue, 26 May 2020 18:55:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519353; bh=NOUY2cFAxW4NOpv/x7vgV6FUGdxcy+oqZ/7YtptmUIs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TL+EsfELdovadTz759QINdor245D5BTQ0UsNIvvO4L6bRMyzrhzEE3oBGbciiu2KQ 23GN93SvgsOjxv1s9Mrbwx9yCrnj7MWVxHthYwFlIZ9jrOXX17egzV+H6OohT1Vo+Z A22r3kR2pWejRYWx3kQODCwW0lmoSFg/+HkBvN78= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, greg@kroah.com Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Guillaume Nault , "David S. Miller" , Giuliano Procida Subject: [PATCH 4.4 34/65] l2tp: lock socket before checking flags in connect() Date: Tue, 26 May 2020 20:52:53 +0200 Message-Id: <20200526183918.173764337@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183905.988782958@linuxfoundation.org> References: <20200526183905.988782958@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guillaume Nault commit 0382a25af3c771a8e4d5e417d1834cbe28c2aaac upstream. Socket flags aren't updated atomically, so the socket must be locked while reading the SOCK_ZAPPED flag. This issue exists for both l2tp_ip and l2tp_ip6. For IPv6, this patch also brings error handling for __ip6_datagram_connect() failures. Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Giuliano Procida Signed-off-by: Greg Kroah-Hartman --- include/net/ipv6.h | 2 ++ net/ipv6/datagram.c | 4 +++- net/l2tp/l2tp_ip.c | 19 ++++++++++++------- net/l2tp/l2tp_ip6.c | 16 +++++++++++----- 4 files changed, 28 insertions(+), 13 deletions(-) --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -915,6 +915,8 @@ int compat_ipv6_setsockopt(struct sock * int compat_ipv6_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); +int __ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, + int addr_len); int ip6_datagram_connect(struct sock *sk, struct sockaddr *addr, int addr_len); int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *addr, int addr_len); --- a/net/ipv6/datagram.c +++ b/net/ipv6/datagram.c @@ -40,7 +40,8 @@ static bool ipv6_mapped_addr_any(const s return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0); } -static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, + int addr_len) { struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; struct inet_sock *inet = inet_sk(sk); @@ -213,6 +214,7 @@ out: fl6_sock_release(flowlabel); return err; } +EXPORT_SYMBOL_GPL(__ip6_datagram_connect); int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) { --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -321,21 +321,24 @@ static int l2tp_ip_connect(struct sock * struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr; int rc; - if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ - return -EINVAL; - if (addr_len < sizeof(*lsa)) return -EINVAL; if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) return -EINVAL; - rc = ip4_datagram_connect(sk, uaddr, addr_len); - if (rc < 0) - return rc; - lock_sock(sk); + /* Must bind first - autobinding does not work */ + if (sock_flag(sk, SOCK_ZAPPED)) { + rc = -EINVAL; + goto out_sk; + } + + rc = __ip4_datagram_connect(sk, uaddr, addr_len); + if (rc < 0) + goto out_sk; + l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; write_lock_bh(&l2tp_ip_lock); @@ -343,7 +346,9 @@ static int l2tp_ip_connect(struct sock * sk_add_bind_node(sk, &l2tp_ip_bind_table); write_unlock_bh(&l2tp_ip_lock); +out_sk: release_sock(sk); + return rc; } --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -383,9 +383,6 @@ static int l2tp_ip6_connect(struct sock int addr_type; int rc; - if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ - return -EINVAL; - if (addr_len < sizeof(*lsa)) return -EINVAL; @@ -402,10 +399,18 @@ static int l2tp_ip6_connect(struct sock return -EINVAL; } - rc = ip6_datagram_connect(sk, uaddr, addr_len); - lock_sock(sk); + /* Must bind first - autobinding does not work */ + if (sock_flag(sk, SOCK_ZAPPED)) { + rc = -EINVAL; + goto out_sk; + } + + rc = __ip6_datagram_connect(sk, uaddr, addr_len); + if (rc < 0) + goto out_sk; + l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; write_lock_bh(&l2tp_ip6_lock); @@ -413,6 +418,7 @@ static int l2tp_ip6_connect(struct sock sk_add_bind_node(sk, &l2tp_ip6_bind_table); write_unlock_bh(&l2tp_ip6_lock); +out_sk: release_sock(sk); return rc;