From owner-freebsd-security Sat Sep 8 8:16: 5 2001 Delivered-To: freebsd-security@freebsd.org Received: from ringworld.nanolink.com (sentinel.office1.bg [217.75.135.254]) by hub.freebsd.org (Postfix) with SMTP id 43C0937B408 for ; Sat, 8 Sep 2001 08:15:59 -0700 (PDT) Received: (qmail 1147 invoked by uid 1000); 8 Sep 2001 15:15:37 -0000 Date: Sat, 8 Sep 2001 18:15:37 +0300 From: Peter Pentchev To: D J Hawkey Jr Cc: Alexander Langer , deepak@ai.net, freebsd-security@FreeBSD.ORG Subject: Re: Kernel-loadable Root Kits Message-ID: <20010908181537.A840@ringworld.oblivion.bg> Mail-Followup-To: D J Hawkey Jr , Alexander Langer , deepak@ai.net, freebsd-security@FreeBSD.ORG References: <200109081052.f88AqRG30016@sheol.localdomain> <20010908141700.A53738@fump.kawo2.rwth-aachen.de> <20010908072542.A57605@sheol.localdomain> <20010908143231.A53801@fump.kawo2.rwth-aachen.de> <20010908074445.A77252@sheol.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20010908074445.A77252@sheol.localdomain>; from hawkeyd@visi.com on Sat, Sep 08, 2001 at 07:44:45AM -0500 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Sat, Sep 08, 2001 at 07:44:45AM -0500, D J Hawkey Jr wrote: > On Sep 08, at 02:32 PM, Alexander Langer wrote: > > > > Thus spake D J Hawkey Jr (hawkeyd@visi.com): > > > > > > This still lets you load own kernel modules. > > > Not if you blow away the /modules directory (note that I haven't tried > > > this). > > > > /me hands Dave a decent C compiler and some C h0h0magic. > > I didn't write "build the kernel without it". > > As I wrote, I hadn't tried it. I take it one cannot remove that tree, > even after seeing that the kernel doesn't need it? I'm meaning run-time > here, not build-time. I believe that what Alex meant is that you can simulate kldload(8)'s functionality in a little C program of your own. Even more than that, kldload(8) itself allows you to specify a full path to a module, not just a filename, so even if you blow away the /modules directory, J. Random Luser can still 'kldload /var/tmp/rkit.kld'. Yes, you can remove /modules; no, that does not gain you any safety. G'luck, Peter -- This sentence every third, but it still comprehensible. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message