From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38638) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SgcXX-0006iw-Kq for qemu-devel@nongnu.org; Mon, 18 Jun 2012 10:02:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SgcXP-0004KF-2z for qemu-devel@nongnu.org; Mon, 18 Jun 2012 10:02:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:5256) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SgcXO-0004Jy-RB for qemu-devel@nongnu.org; Mon, 18 Jun 2012 10:02:39 -0400 From: Paul Moore Date: Mon, 18 Jun 2012 10:02:31 -0400 Message-ID: <20307415.4nEIkSHNDB@sifl> In-Reply-To: <20120618135535.GX28026@redhat.com> References: <3272318.IIWAhra0IR@sifl> <20120618135535.GX28026@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [Qemu-devel] [RFC] [PATCHv2 2/2] Adding basic calls to libseccomp in vl.c List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: Blue Swirl , qemu-devel@nongnu.org, Eduardo Otubo On Monday, June 18, 2012 02:55:35 PM Daniel P. Berrange wrote: > On Mon, Jun 18, 2012 at 09:52:44AM -0400, Paul Moore wrote: > > On Monday, June 18, 2012 09:31:03 AM Daniel P. Berrange wrote: > > > On Fri, Jun 15, 2012 at 05:02:19PM -0400, Paul Moore wrote: > > > > On Friday, June 15, 2012 07:06:10 PM Blue Swirl wrote: > > > > > I think allowing execve() would render seccomp pretty much useless. > > > > > > > > Not necessarily. > > > > > > > > I'll agree that it does seem a bit odd to allow execve(), but there is > > > > still value in enabling seccomp to disable potentially > > > > buggy/exploitable > > > > syscalls. Let's not forget that we have over 300 syscalls on x86_64, > > > > not > > > > including the 32 bit versions, and even if we add all of the new > > > > syscalls > > > > suggested in this thread we are still talking about a small subset of > > > > syscalls. As far as security goes, the old adage of "less is more" > > > > applies. > > > > > > I can sort of see this argument, but *only* if the QEMU process is being > > > run under a dedicated, fully unprivileged (from a DAC pov) user, > > > completely > > > separate from anything else on the system. > > > > > > Or, of course, for a QEMU already confined by SELinux. > > > > Agreed ... and considering at least one major distribution takes this > > approach it seems like reasonable functionality to me. Confining QEMU, > > either through DAC and/or MAC, when faced with potentially malicious > > guests is just good sense. > > Good, I'm not missing anything then. I'd suggest that future iterations > of these patches explicitly mention the deployment scenarios in which > this technology is able to offer increases security, and also describe > the scenarios where it will not improve things. Sounds like a reasonable request to me. -- paul moore security and virtualization @ redhat