From: Adrian Bunk <bunk@kernel.org>
To: David Newall <david@davidnewall.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
Bill Davidsen <davidsen@tmr.com>,
Philipp Marek <philipp@marek.priv.at>,
7eggert@gmx.de, Alan Cox <alan@lxorguk.ukuu.org.uk>,
majkls <majkls@prepere.com>,
linux-kernel@vger.kernel.org
Subject: Re: Chroot bug (was: sys_chroot+sys_fchdir Fix)
Date: Tue, 25 Sep 2007 17:32:08 +0200 [thread overview]
Message-ID: <20070925153208.GO6800@stusta.de> (raw)
In-Reply-To: <46F924E3.50205@davidnewall.com>
On Wed, Sep 26, 2007 at 12:40:27AM +0930, David Newall wrote:
> Miloslav Semler pointed out that a root process can chdir("..") out of its
> chroot. Although this is documented in the man page, it conflicts with the
> essential function, which is to change the root directory of the process.
> In addition to any creative uses, for example Philipp Marek's loading
> dynamic libraries, it seems clear that the prime purpose of chroot is to
> aid security. Being able to cd your way out is handy for the bad guys, but
> the good guys don't need it; there are a thousand better, safer solutions.
>...
The bad guys most likely also now other tricks to escape the chroot.
If you are root in the chroot you can e.g. mount the partition with the
root filesystem inside the chroot.
If a bad guy becomes root inside a chroot it's game over.
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
next prev parent reply other threads:[~2007-09-25 15:31 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <952DN-83o-31@gated-at.bofh.it>
[not found] ` <954cl-29C-3@gated-at.bofh.it>
[not found] ` <95ctn-74b-15@gated-at.bofh.it>
[not found] ` <95cMH-7um-19@gated-at.bofh.it>
[not found] ` <95gdA-4OZ-7@gated-at.bofh.it>
2007-09-20 11:13 ` sys_chroot+sys_fchdir Fix Bodo Eggert
2007-09-20 11:59 ` Philipp Marek
2007-09-20 12:52 ` majkls
2007-09-20 16:06 ` David Newall
2007-09-20 16:17 ` Philipp Marek
2007-09-20 18:02 ` David Newall
2007-09-20 20:53 ` Bill Davidsen
2007-09-21 8:29 ` David Newall
2007-09-24 21:32 ` Serge E. Hallyn
2007-09-24 22:04 ` David Newall
2007-09-24 23:00 ` Serge E. Hallyn
2007-09-25 7:45 ` David Newall
2007-09-25 11:49 ` Serge E. Hallyn
2007-09-25 13:58 ` David Newall
2007-09-25 15:10 ` Chroot bug (was: sys_chroot+sys_fchdir Fix) David Newall
2007-09-25 15:20 ` Jan Engelhardt
2007-09-25 15:39 ` Chroot bug Miloslav Semler
2007-09-25 15:41 ` David Newall
2007-09-25 15:48 ` Jan Engelhardt
2007-09-25 16:19 ` Miloslav Semler
2007-09-25 16:52 ` Jan Engelhardt
2007-09-25 17:00 ` Miloslav Semler
2007-09-25 17:05 ` Jan Engelhardt
2007-09-25 17:09 ` Miloslav Semler
2007-09-25 17:09 ` Al Viro
2007-09-25 17:19 ` Miloslav Semler
2007-09-25 16:53 ` Serge E. Hallyn
2007-09-25 20:51 ` David Newall
2007-09-25 15:30 ` Chroot bug (was: sys_chroot+sys_fchdir Fix) Alan Cox
2007-09-25 15:35 ` Chroot bug David Newall
2007-09-25 15:48 ` Alan Cox
2007-09-25 15:47 ` Jan Engelhardt
2007-09-25 23:50 ` David Newall
2007-09-26 0:18 ` Alan Cox
2007-09-26 10:24 ` David Newall
2007-09-26 10:47 ` Alan Cox
2007-09-26 11:06 ` David Newall
2007-09-26 11:20 ` Alan Cox
[not found] ` <46FA41B4.9040104@prepere.com>
[not found] ` <20070926123522.54ffd56f@the-village.bc.nu>
2007-09-26 11:34 ` Miloslav Semler
2007-09-26 14:09 ` Alan Cox
2007-09-26 13:13 ` Bongani Hlope
2007-09-26 0:55 ` Adrian Bunk
2007-09-26 5:21 ` Kyle Moffett
2007-09-26 5:25 ` Willy Tarreau
2007-09-26 10:27 ` David Newall
2007-09-26 10:45 ` Olivier Galibert
2007-09-26 11:13 ` David Newall
2007-09-26 13:18 ` linux-os (Dick Johnson)
2007-09-26 15:02 ` Olivier Galibert
2007-09-26 12:54 ` Kyle Moffett
2007-09-26 13:11 ` Miloslav Semler
2007-09-26 13:42 ` Al Viro
2007-09-26 14:51 ` Miloslav Semler
2007-09-26 14:02 ` Kyle Moffett
2007-09-26 15:01 ` Miloslav Semler
2007-09-27 13:49 ` Jiri Kosina
2007-09-25 16:33 ` Arjan van de Ven
2007-09-25 15:32 ` Adrian Bunk [this message]
2007-09-25 15:43 ` Miloslav Semler
2007-09-25 16:02 ` Adrian Bunk
2007-09-26 19:23 ` Chroot bug (was: sys_chroot+sys_fchdir Fix) Bodo Eggert
2007-09-24 23:02 ` sys_chroot+sys_fchdir Fix Serge E. Hallyn
[not found] ` <95UE2-1oR-19@gated-at.bofh.it>
[not found] ` <95V72-2ly-17@gated-at.bofh.it>
[not found] ` <97pG8-3B5-47@gated-at.bofh.it>
[not found] ` <97sX2-p1-3@gated-at.bofh.it>
2007-09-26 9:38 ` Nick Craig-Wood
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