From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51819) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cBJ1x-0001OD-Ff for qemu-devel@nongnu.org; Mon, 28 Nov 2016 05:19:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cBJ1t-0005hm-7V for qemu-devel@nongnu.org; Mon, 28 Nov 2016 05:19:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51828) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cBJ1t-0005hi-2m for qemu-devel@nongnu.org; Mon, 28 Nov 2016 05:19:21 -0500 Date: Mon, 28 Nov 2016 10:19:16 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20161128101916.GB2148@work-vm> References: <290015b23a9ec5033ee65209882dcbc0@openmailbox.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <290015b23a9ec5033ee65209882dcbc0@openmailbox.org> Subject: Re: [Qemu-devel] QEMU soundcards vulnerable to jack retasking? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: bancfc@openmailbox.org Cc: qemu-devel@nongnu.org * bancfc@openmailbox.org (bancfc@openmailbox.org) wrote: > Recent security research shows that soundcards support surreptitiously > switching line-out jacks into line-in by modifying the software stack. The > way modern speakers and headphones are designed makes them readily usable as > microphones. The Intel High Definition (HD) Audio standards which all modern > consumer soundcards are based mandates this stupidity. > > https://arxiv.org/ftp/arxiv/papers/1611/1611.07350.pdf > > Does anyone know if QEMU's emulated sound devices follow this standard? If > yes then a malicious guest that can modify the virt sound hardware can turn > PC speakers into surveillance devices even if the microphone is disabled on > the host. The only solution is completely denying untrusted VMs access to a > virtual sound device. I think it's reasonably isolated; the emulated audio controller ends up using normal pulseaudio/alsa etc to talk to your host's audio system - so I don't think it should be able to screw around with low level settings of the codecs. Dave > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK