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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 56AA7C43441 for ; Sun, 11 Nov 2018 20:04:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23D9920869 for ; Sun, 11 Nov 2018 20:04:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23D9920869 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731101AbeKLFx4 (ORCPT ); Mon, 12 Nov 2018 00:53:56 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:51668 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726508AbeKLFxz (ORCPT ); Mon, 12 Nov 2018 00:53:55 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvt0-0000l4-Lt; Sun, 11 Nov 2018 19:59:10 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsS-0001YP-DN; Sun, 11 Nov 2018 19:58:36 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Guillaume Nault" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 143/366] l2tp: reject creation of non-PPP sessions on L2TPv2 tunnels In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Guillaume Nault commit de9bada5d389903f4faf33980e6a95a2911c7e6d upstream. The /proc/net/pppol2tp handlers (pppol2tp_seq_*()) iterate over all L2TPv2 tunnels, and rightfully expect that only PPP sessions can be found there. However, l2tp_netlink accepts creating Ethernet sessions regardless of the underlying tunnel version. This confuses pppol2tp_seq_session_show(), which expects that l2tp_session_priv() returns a pppol2tp_session structure. When the session is an Ethernet pseudo-wire, a struct l2tp_eth_sess is returned instead. This leads to invalid memory access when pppol2tp_session_get_sock() later tries to dereference ps->sk. Fixes: d9e31d17ceba ("l2tp: Add L2TP ethernet pseudowire support") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/l2tp/l2tp_netlink.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -460,6 +460,12 @@ static int l2tp_nl_cmd_session_create(st goto out_tunnel; } + /* L2TPv2 only accepts PPP pseudo-wires */ + if (tunnel->version == 2 && cfg.pw_type != L2TP_PWTYPE_PPP) { + ret = -EPROTONOSUPPORT; + goto out_tunnel; + } + if (tunnel->version > 2) { if (info->attrs[L2TP_ATTR_OFFSET]) cfg.offset = nla_get_u16(info->attrs[L2TP_ATTR_OFFSET]);