Message-Id: <1258042007.31158.1344897055@webmail.messagingengine.com>
From: "Henrique de Moraes Holschuh" <hmh@hmh.eng.br>
To: "Alan Cox" <alan@lxorguk.ukuu.org.uk>
Cc: "Robert Hancock" <hancockrwd@gmail.com>,
       "Anton D. Kachalov" <mouse@mayc.ru>, linux-kernel@vger.kernel.org
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References: <4AFACC03.7080209@mayc.ru><4AFB2822.30906@gmail.com><20091112021209.GA21625@khazad-dum.debian.net>
 <20091112110949.339c0c64@lxorguk.ukuu.org.uk>
Subject: Re: Reading /dev/mem by dd
In-Reply-To: <20091112110949.339c0c64@lxorguk.ukuu.org.uk>
Date: Thu, 12 Nov 2009 14:06:47 -0200
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On Thu, 12 Nov 2009 11:09 +0000, "Alan Cox" <alan@lxorguk.ukuu.org.uk> wrote:
> On Thu, 12 Nov 2009 00:12:09 -0200 Henrique de Moraes Holschuh
> <hmh@hmh.eng.br> wrote:
> > On Wed, 11 Nov 2009, Robert Hancock wrote:
> > > I don't think that we prevent any access to device registers in
> > > /dev/mem - if you read something that has side effects and
> > > something breaks, well I guess you get to keep both pieces :-)
> > > There's a reason it's root-only..
> >
> > We should.  Imaging /dev/mem is one of the oldest tricks in the book
> > of the forensics people, they do it to live systems to help track
> > down WTF happened to a compromised host.  This kind of crap bites
> > them hard.
>
> Any forensics person who images /dev/mem needs to go back to school.

While I do agree with you, I can assure you they do it all the time at
least around here, and it is still listed as "best practice" in the
notebooks of many.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh

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