Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756501AbXIYQUG (ORCPT ); Tue, 25 Sep 2007 12:20:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756154AbXIYQTn (ORCPT ); Tue, 25 Sep 2007 12:19:43 -0400 Received: from h90-m1.hosting90.cz ([81.0.225.70]:39379 "EHLO h90-m1.hosting90.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753757AbXIYQTm (ORCPT ); Tue, 25 Sep 2007 12:19:42 -0400 Message-ID: <46F9351D.8020906@prepere.com> Date: Tue, 25 Sep 2007 18:19:41 +0200 From: Miloslav Semler User-Agent: IceDove 1.5.0.12 (X11/20070607) MIME-Version: 1.0 To: Jan Engelhardt CC: serge@hallyn.com, davidsen@tmr.com, philipp@marek.priv.at, 7eggert@gmx.de, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org Subject: Re: Chroot bug References: <56705.193.171.152.61.1190289559.squirrel@webmail.marek.priv.at> <46F29A9A.4070806@davidnewall.com> <200709201817.17282@x5> <46F2B59F.8090709@davidnewall.com> <46F2DDD0.3030500@tmr.com> <46F380E4.4040606@davidnewall.com> <20070924213215.GA32716@vino.hallyn.com> <46F83474.5040503@davidnewall.com> <20070924230008.GA3160@vino.hallyn.com> <46F8BC8A.7080006@davidnewall.com> <20070925114947.GA9721@vino.hallyn.com> <46F91417.9050600@davidnewall.com> <46F924E3.50205@davidnewall.com> <46F92C17.3060405@davidnewall.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 689 Lines: 28 >>> So what? Just do this: chdir into the root after chroot. >>> >> I don't think so. His exploit just got me all the way out of a chroot within a >> chroot within a chroot, inclusive of lots of chdirs. >> > > Close all fds that point to directories outside the root ;-) > > This does not help. Let's try: chroot somewhere mkdir foo fd = open / chroot foo fchdir fd chdir ".." .... chdir ".." chroot "." so you are in root. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/