From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1Vr9OU-0003YJ-3v for mharc-grub-devel@gnu.org; Thu, 12 Dec 2013 11:45:46 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58663) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vr9OO-0003Xv-04 for grub-devel@gnu.org; Thu, 12 Dec 2013 11:45:44 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Vr9OG-00048T-0N for grub-devel@gnu.org; Thu, 12 Dec 2013 11:45:39 -0500 Received: from mail-we0-x22a.google.com ([2a00:1450:400c:c03::22a]:60749) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Vr9OF-00048J-Oq for grub-devel@gnu.org; Thu, 12 Dec 2013 11:45:31 -0500 Received: by mail-we0-f170.google.com with SMTP id w61so709481wes.1 for ; Thu, 12 Dec 2013 08:45:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=tFV3jCr9M0QD7Eey2uQaIuzydpPCH7wNGoURLSj02EQ=; b=L02JkG8xUgp21pUnHkxTzeysdYTmyn9N1c13sw8uXwZytDQ8Pp0OWc1WCq2xD/Ao3a Sz+6BXNrYC3f3YWSIuCU7QDL7BXRxANBQY+8E2TzaN0zTb7KH7FifF4ga6KjH8S6bbW/ 0/nakg1g0nPVcVbOA4zi84sRP/qI5whoAVnV9X7p+3Q+yIB17ZaXhEa/XqjEPpRQ4DDF bVWn0f16F7AF60R00e7ukhFicD7sZEOTa1SdhWSqjgwcR5Ad5bEpgiZBRgCozRjHLzOE bbxYOMLqG9WekDRkdHSJAEAaa2zLZN9MiP0l9HkiL+McZwd7igwD28YjSWbZ7LvPWdsO 37bg== MIME-Version: 1.0 X-Received: by 10.180.14.134 with SMTP id p6mr30009476wic.6.1386866730813; Thu, 12 Dec 2013 08:45:30 -0800 (PST) Received: by 10.180.39.193 with HTTP; Thu, 12 Dec 2013 08:45:30 -0800 (PST) Received: by 10.180.39.193 with HTTP; Thu, 12 Dec 2013 08:45:30 -0800 (PST) In-Reply-To: <20131212163907.GG1431@riva.ucam.org> References: <20131212153643.GA1431@riva.ucam.org> <20131212153741.GD1431@riva.ucam.org> <20131212163907.GG1431@riva.ucam.org> Date: Thu, 12 Dec 2013 17:45:30 +0100 Message-ID: Subject: Re: [PATCH 3/4] Build grub.xen. From: "Vladimir 'phcoder' Serbinenko" To: The development of GNU GRUB Content-Type: multipart/alternative; boundary=f46d04155418d74d7604ed5912df X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2a00:1450:400c:c03::22a X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Dec 2013 16:45:45 -0000 --f46d04155418d74d7604ed5912df Content-Type: text/plain; charset=ISO-8859-1 No I meant full access to just obe of guest partitions. E.g. FTP may be using separate partition and non-admins may have control over it. If system has some kind of automatic user creation and /home is separate someone may register as boot or grub and put grub.xen in his directory. If /tmp is on separate partition and not in RAM then everybody can put grub.xen to /tmp/grub/grub.xen On Dec 12, 2013 5:39 PM, "Colin Watson" wrote: > On Thu, Dec 12, 2013 at 05:24:50PM +0100, Vladimir 'phcoder' Serbinenko > wrote: > > This config has a security problem. If a user has full acces to some > > partition (e.g. fto server partition) he can put grub.xen there and load > > his own code > > Only in the domU context, though. If a user has full access to a guest > filesystem then of course they can run code in the domU. This seems > unsurprising and not a problem? > > -- > Colin Watson [cjwatson@ubuntu.com] > > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > https://lists.gnu.org/mailman/listinfo/grub-devel > --f46d04155418d74d7604ed5912df Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

No I meant full access to just obe of guest partitions. E.g. FTP may be = using separate partition and non-admins may have control over it. If system= has some kind of automatic user creation and /home is separate someone may= register as boot or grub and put grub.xen in his directory. If /tmp is on = separate partition and not in RAM then everybody can put grub.xen to /tmp/g= rub/grub.xen

On Dec 12, 2013 5:39 PM, "Colin Watson"= ; <cjwatson@ubuntu.com> wr= ote:
On Thu, Dec 12, 2013 at 05:24:50PM +0100, Vladimir 'phcoder' Serbin= enko wrote:
> This config has a security problem. If a user has full acces to some > partition (e.g. fto server partition) he can put grub.xen there and lo= ad
> his own code

Only in the domU context, though. =A0If a user has full access to a guest filesystem then of course they can run code in the domU. =A0This seems
unsurprising and not a problem?

--
Colin Watson =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = =A0 =A0 =A0 =A0 [cjwatson@ubuntu.com= ]

_______________________________________________
Grub-devel mailing list
Grub-devel@gnu.org
https://lists.gnu.org/mailman/listinfo/grub-devel
--f46d04155418d74d7604ed5912df--