From: ebiederm@xmission.com (Eric W. Biederman)
To: Ville Herva <vherva@niksula.hut.fi>
Cc: James Stevenson <james@stev.org>,
ebiederm@xmission.com, linux-kernel@vger.kernel.org
Subject: Re: One for the Security Guru's
Date: 24 Oct 2002 10:46:39 -0600 [thread overview]
Message-ID: <m1znt3rdhs.fsf@frodo.biederman.org> (raw)
In-Reply-To: <20021024101126.GQ147946@niksula.cs.hut.fi>
Ville Herva <vherva@niksula.hut.fi> writes:
> On Wed, Oct 23, 2002 at 11:15:14PM +0100, you [James Stevenson] wrote:
> >
> > As to load a module you must be root and if you are root you
> > can read / write disks. Thus you could recompile your own kernel
> > install it try to force a crash or a reboot which is not hard as root
> > and the person may not even notice that the kernel has grown by a few
> > bytes after the crash.
>
> Which is why some people configure kernels not to support installing modules
> and only use read-only media (e.g. CD-R) for booting. Sure, there's still
> the /dev/kmem hole, but this closes 2 classes of attacks - loading rootkit
> module and booting with a hacked kernel in straight-forward way.
>
> BTW, this might be a reason to make kexec syscall to be a config option (if
> it isn't already.)
It already is a config option.
Eric
next prev parent reply other threads:[~2002-10-24 16:44 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-23 13:02 One for the Security Guru's Robert L. Harris
2002-10-23 13:13 ` John Jasen
2002-10-23 13:20 ` Keith Owens
2002-10-24 7:56 ` Greg KH
2002-10-23 13:45 ` Alan Cox
2002-10-23 13:59 ` Gilad Ben-ossef
2002-10-23 22:14 ` James Cleverdon
2002-10-23 22:17 ` James Stevenson
2002-10-23 22:39 ` James Cleverdon
2002-10-23 22:44 ` James Stevenson
2002-10-24 6:12 ` Gilad Ben-Yossef
2002-11-06 21:39 ` Florian Weimer
2002-10-23 14:57 ` Richard B. Johnson
2002-10-23 17:56 ` Gerhard Mack
2002-10-24 9:38 ` Henning P. Schmiedehausen
[not found] ` <ap8f36$8ge$1@dstl.gov.uk>
2002-10-24 10:01 ` Tony Gale
2002-10-24 16:13 ` Gerhard Mack
2002-10-24 16:39 ` Henning P. Schmiedehausen
2002-10-24 16:34 ` David Lang
2002-10-24 17:04 ` Gilad Ben-Yossef
2002-10-25 9:44 ` Henning Schmiedehausen
2002-10-25 20:52 ` H. Peter Anvin
2002-10-26 10:43 ` Henning P. Schmiedehausen
2002-10-27 10:17 ` Rogier Wolff
2002-10-28 7:47 ` Chris Wedgwood
2002-10-24 22:02 ` Danny Lepage
2002-10-25 9:40 ` Henning Schmiedehausen
2002-10-24 14:23 ` Gilad Ben-ossef
2002-10-25 4:09 ` Stephen Satchell
2002-10-25 13:47 ` Stephen Frost
2002-10-26 10:38 ` Rogier Wolff
2002-10-26 9:44 ` Rogier Wolff
2002-10-26 10:46 ` Henning P. Schmiedehausen
2002-10-23 16:23 ` Henning P. Schmiedehausen
2002-10-23 17:55 ` David Lang
2002-10-23 19:46 ` H. Peter Anvin
2002-10-23 22:15 ` James Stevenson
2002-10-24 9:47 ` Henning P. Schmiedehausen
2002-10-25 12:28 ` Daniel Egger
2002-10-25 15:22 ` Alex Riesen
2002-10-25 16:38 ` Stephen Satchell
2002-10-25 18:21 ` [OT] " J Sloan
2002-10-26 10:40 ` OT " Rogier Wolff
2002-10-24 10:11 ` Ville Herva
2002-10-24 11:09 ` Henning P. Schmiedehausen
2002-10-24 11:55 ` Alan Cox
2002-10-24 14:40 ` Henning P. Schmiedehausen
2002-10-24 15:36 ` Alan Cox
2002-10-24 16:46 ` Eric W. Biederman [this message]
2002-10-24 6:04 ` David Wagner
-- strict thread matches above, loose matches on Subject: below --
2002-10-23 21:49 Hank Leininger
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