From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38012) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fOpCA-0004yt-2I for qemu-devel@nongnu.org; Fri, 01 Jun 2018 14:54:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fOpC6-000631-4X for qemu-devel@nongnu.org; Fri, 01 Jun 2018 14:54:38 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:56668 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fOpC5-00062b-VY for qemu-devel@nongnu.org; Fri, 01 Jun 2018 14:54:34 -0400 Date: Fri, 1 Jun 2018 19:54:29 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20180601185429.GB2532@work-vm> References: <40602400-cae4-e175-e7ce-10ac70ba52f5@riseup.net> <20180601113444.GG8687@stefanha-x1.localdomain> <20180601184855-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180601184855-mutt-send-email-mst@kernel.org> Subject: Re: [Qemu-devel] Virtio-net drivers immune to Nethammer? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: procmem , Stefan Hajnoczi , jasowang@redhat.com, qemu-devel@nongnu.org, whonix-devel@whonix.org * Michael S. Tsirkin (mst@redhat.com) wrote: > On Fri, Jun 01, 2018 at 01:15:44PM +0000, procmem wrote: > > > > > > Stefan Hajnoczi: > > > On Mon, May 21, 2018 at 11:24:43PM +0000, procmem wrote: > > >> Hi I'm a privacy distro maintainer investigating the implications of the > > >> newly published nethammer attack [0] on KVM guests particularly the > > >> virtio-net drivers. The summary of the paper is that rowhammer can be > > >> remotely triggered by feeding susceptible* network driver crafted > > >> traffic. This attack can do all kinds of nasty things such as modifying > > >> SSL certs on the victim system. > > >> > > >> * Susceptible drivers are those relying on Intel CAT, uncached memory or > > >> the clflush instruction. > > >> > > >> My question is, do virtio-net drivers do any of these things? > > > I have CCed Michael Tsirkin and Jason Wang, the virtio maintainers. > > > > > >> *** > > >> > > >> [0] https://arxiv.org/abs/1805.04956 > > >> > > >> > > >> > > > > Thanks :) I thought my message was forgotten > > > I don't think virtio is using either of these. > > Linux does support CAT AFAIK but it has nothing to do with virtio. Isn't the idea to misuse CAT to detect something about access patterns; so it's not about it actually being related? Dave > -- > MST > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK