From: "H. Peter Anvin" <hpa@zytor.com>
To: Colin Walters <walters@verbum.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
morgan@kernel.org, serue@us.ibm.com, dhowells@redhat.com,
kzak@redhat.com
Subject: Re: chroot(2) and bind mounts as non-root
Date: Wed, 07 Dec 2011 12:34:28 -0800 [thread overview]
Message-ID: <4EDFCDD4.2080603@zytor.com> (raw)
In-Reply-To: <1323280461.10724.13.camel@lenny>
On 12/07/2011 09:54 AM, Colin Walters wrote:
>
> The historical reason one can't call chroot(2) as non-root is because of
> setuid binaries (hard link a setuid binary into chroot of your choice
> with trojaned libc.so).
No. The historical reason is that it lets anyone escape a chroot jail:
mkdir("jailbreak", 0666);
chroot("jailbreak");
/* Now the cwd is outside the root, and therefore not bound by
it, walk the chain of .. directories until they don't change
anymore */
chroot("."); /* Change the root to the system root */
Oops.
-hpa
next prev parent reply other threads:[~2011-12-07 20:34 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-07 17:54 chroot(2) and bind mounts as non-root Colin Walters
2011-12-07 19:36 ` John Stoffel
2011-12-08 16:10 ` Colin Walters
2011-12-08 18:14 ` John Stoffel
2011-12-08 18:26 ` Colin Walters
2011-12-09 0:49 ` Sven-Haegar Koch
2011-12-09 14:55 ` John Stoffel
2011-12-09 15:06 ` Colin Walters
2011-12-08 17:04 ` Arnd Bergmann
2011-12-08 17:15 ` Colin Walters
2011-12-07 19:40 ` Andy Lutomirski
2011-12-08 16:58 ` Colin Walters
2011-12-07 20:34 ` H. Peter Anvin [this message]
2011-12-07 20:54 ` Alan Cox
2011-12-15 18:55 ` Andrew G. Morgan
2011-12-16 15:44 ` Colin Walters
2011-12-18 1:22 ` Andrew G. Morgan
2011-12-18 15:19 ` Colin Walters
2011-12-10 5:29 ` Serge E. Hallyn
2011-12-12 16:41 ` Colin Walters
2011-12-12 23:11 ` Serge E. Hallyn
2011-12-15 20:56 ` Colin Walters
2011-12-16 6:14 ` Eric W. Biederman
2011-12-18 16:01 ` Colin Walters
2011-12-19 0:55 ` Eric W. Biederman
2011-12-19 4:06 ` Serge E. Hallyn
2011-12-19 9:22 ` Eric W. Biederman
2011-12-20 16:49 ` Colin Walters
2011-12-20 21:23 ` Colin Walters
2011-12-21 18:15 ` Steve Grubb
2012-01-03 23:13 ` Eric W. Biederman
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