From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755743Ab2F0JVx (ORCPT ); Wed, 27 Jun 2012 05:21:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:15164 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755139Ab2F0JVu (ORCPT ); Wed, 27 Jun 2012 05:21:50 -0400 Date: Wed, 27 Jun 2012 12:21:50 +0300 From: "Michael S. Tsirkin" To: Alex Williamson Cc: avi@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, jan.kiszka@siemens.com Subject: Re: [PATCH v2 3/6] kvm: Sanitize KVM_IRQFD flags Message-ID: <20120627092150.GD17507@redhat.com> References: <20120627044758.23698.249.stgit@bling.home> <20120627050924.23698.65802.stgit@bling.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120627050924.23698.65802.stgit@bling.home> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 26, 2012 at 11:09:32PM -0600, Alex Williamson wrote: > We only know of one so far. > > Signed-off-by: Alex Williamson Ugh. So we have a bug: we should have sanitized the fields. If there's buggy userspace that only set the low bit it will break with this change. Is it too late now? Do we need KVM_IRQFD2 which sanitized fields properly? Avi? > --- > > virt/kvm/eventfd.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c > index c307c24..7d7e2aa 100644 > --- a/virt/kvm/eventfd.c > +++ b/virt/kvm/eventfd.c > @@ -340,6 +340,9 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args) > int > kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args) > { > + if (args->flags & ~KVM_IRQFD_FLAG_DEASSIGN) > + return -EINVAL; > + > if (args->flags & KVM_IRQFD_FLAG_DEASSIGN) > return kvm_irqfd_deassign(kvm, args); >