From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 04/47] KVM: x86: Disallow hypercalls for guest callers in rings > 0 Date: Sun, 04 Oct 2009 18:26:15 +0200 Message-ID: <4AC8CCA7.40804@redhat.com> References: <1251282609-12835-1-git-send-email-avi@redhat.com> <1251282609-12835-5-git-send-email-avi@redhat.com> <1254293895.5468.2775.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: kvm@vger.kernel.org To: =?ISO-8859-1?Q?Jan_L=FCbbe?= Return-path: Received: from mx1.redhat.com ([209.132.183.28]:43518 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755163AbZJDQ0s (ORCPT ); Sun, 4 Oct 2009 12:26:48 -0400 In-Reply-To: <1254293895.5468.2775.camel@localhost> Sender: kvm-owner@vger.kernel.org List-ID: On 09/30/2009 08:58 AM, Jan L=FCbbe wrote: > Hi! > > On Wed, 2009-08-26 at 13:29 +0300, Avi Kivity wrote: > =20 >> From: Jan Kiszka >> >> So far unprivileged guest callers running in ring 3 can issue, e.g.,= MMU >> hypercalls. Normally, such callers cannot provide any hand-crafted M= MU >> command structure as it has to be passed by its physical address, bu= t >> they can still crash the guest kernel by passing random addresses. >> >> To close the hole, this patch considers hypercalls valid only if iss= ued >> from guest ring 0. This may still be relaxed on a per-hypercall base= in >> the future once required. >> =20 > Does kvm-72 (used by Debian and Ubuntu in stable releases) have the > problem? If yes, would the approach in this fix also work there? > > =20 Probably yes to both. --=20 error compiling committee.c: too many arguments to function