From: David Newall <david@davidnewall.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Bill Davidsen <davidsen@tmr.com>, majkls <majkls@prepere.com>,
bunk@fs.tum.de, linux-kernel@vger.kernel.org
Subject: Re: sys_chroot+sys_fchdir Fix
Date: Thu, 20 Sep 2007 07:54:22 +0930 [thread overview]
Message-ID: <46F1A196.8060108@davidnewall.com> (raw)
In-Reply-To: <20070919194559.36015307@the-village.bc.nu>
> Normal users cannot use chroot() themselves so they can't use chroot to
> get back out
I think Bill is right, that this is to fix a method that non-root
processes can use to escape their chroot. The exploit, which is
documented in chroot(2)*, is to chdir("..") your way out. Who'd have
thought it? Only root can do that, but even that seems wrong. Chroot
should be chroot and that should be the end of it.
It looks to me like Miloslav has found a bug, although I suspect there's
a simpler solution because non-root is already prevented from escaping
this way.
David
* In particular, the superuser can escape from a ‘chroot jail’ by doing
‘mkdir foo; chroot foo; cd ..’.
next prev parent reply other threads:[~2007-09-19 22:24 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-19 7:19 sys_chroot+sys_fchdir Fix majkls
2007-09-19 9:40 ` Alan Cox
2007-09-19 18:27 ` Bill Davidsen
2007-09-19 18:45 ` Alan Cox
2007-09-19 22:24 ` David Newall [this message]
2007-09-21 17:39 ` Phillip Susi
2007-09-21 18:10 ` Alan Cox
2007-09-25 20:53 ` Phillip Susi
2007-09-26 0:23 ` Al Viro
2007-09-26 10:34 ` David Newall
2007-09-26 11:21 ` Alan Cox
2007-09-26 11:22 ` David Newall
2007-09-26 11:38 ` Alan Cox
2007-09-26 11:56 ` David Newall
2007-09-26 14:10 ` Alan Cox
2007-09-26 15:03 ` Chris Adams
2007-09-26 16:54 ` David Newall
2007-09-26 17:04 ` Alan Cox
2007-09-26 17:18 ` David Newall
2007-09-26 17:29 ` Alan Cox
2007-09-26 17:28 ` David Newall
2007-09-26 18:40 ` Al Viro
2007-09-26 19:24 ` Christer Weinigel
2007-09-26 21:19 ` David Newall
2007-09-26 21:55 ` Adrian Bunk
2007-09-26 23:35 ` David Newall
2007-09-27 0:01 ` Adrian Bunk
2007-09-27 3:59 ` Al Viro
2007-09-27 6:42 ` David Newall
2007-09-27 6:53 ` Adrian Bunk
2007-09-27 7:28 ` Christer Weinigel
2007-09-27 11:23 ` Theodore Tso
2007-09-27 14:36 ` Bill Davidsen
2007-09-28 1:06 ` David Newall
[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 ` 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
2007-09-24 23:02 ` 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
[not found] <fa.1U6+49SWHSlhuK5/3PBckFWAbXU@ifi.uio.no>
[not found] ` <fa.WASh5K8oOF4DAq3sSYtIlWNCdWQ@ifi.uio.no>
[not found] ` <fa.X6MeYG+PmN8/e5zfGij80quLaws@ifi.uio.no>
[not found] ` <fa./eIdqiAY0Mx9xHl6ESobHaLKJBM@ifi.uio.no>
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