kern/55568: DUMP has access to block devices in a JAIL

Kris Kennaway kris at
Wed Oct 8 15:30:18 PDT 2003

The following reply was made to PR kern/55568; it has been noted by GNATS.

From: Kris Kennaway <kris at>
To: mjoyner <mjoyner at>
Cc: FreeBSD-gnats-submit at
Subject: Re: kern/55568: DUMP has access to block devices in a JAIL
Date: Wed, 8 Oct 2003 15:23:02 -0700

 Content-Type: text/plain; charset=us-ascii
 Content-Disposition: inline
 On Wed, Aug 13, 2003 at 09:04:06PM -0400, mjoyner wrote:
 >          A jailed root user can use DUMP and gain a snapshot of the
 > entire disk.
 >          From there the jailed root user can restore files from the HOST
 >          or any other jails at their leisure.
 Only if the administrator has configured the jail with the raw disk
 devices.  As you note, this is a security risk.
 >          Even if DEVFS is not mounted, a root user could possibly create a
 >          device node anyways, and one needs TTYS anyways.
 I believe this to be untrue.  root cannot make device nodes once
 inside a jail.
 Content-Type: application/pgp-signature
 Content-Disposition: inline
 Version: GnuPG v1.2.3 (FreeBSD)

More information about the freebsd-bugs mailing list