Date: Tue, 25 Sep 2007 17:48:45 +0200 (CEST)
From: Jan Engelhardt <jengelh@computergmbh.de>
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>,
       bunk@fs.tum.de, linux-kernel@vger.kernel.org
Subject: Re: Chroot bug
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On Sep 26 2007 01:11, David Newall wrote:
> Jan Engelhardt wrote:
>> On Sep 26 2007 00:40, David Newall wrote:
>>   
>> > Miloslav Semler pointed out that a root process can chdir("..") out of its
>> > chroot.
>> 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 ;-)

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