From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754219AbdJCMdU (ORCPT ); Tue, 3 Oct 2017 08:33:20 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34770 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753092AbdJCMdT (ORCPT ); Tue, 3 Oct 2017 08:33:19 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jim Mattson , David Hildenbrand , Paolo Bonzini Subject: [PATCH 4.13 085/110] kvm: nVMX: Dont allow L2 to access the hardware CR8 Date: Tue, 3 Oct 2017 14:29:47 +0200 Message-Id: <20171003114244.730824742@linuxfoundation.org> X-Mailer: git-send-email 2.14.2 In-Reply-To: <20171003114241.408583531@linuxfoundation.org> References: <20171003114241.408583531@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jim Mattson commit 51aa68e7d57e3217192d88ce90fd5b8ef29ec94f upstream. If L1 does not specify the "use TPR shadow" VM-execution control in vmcs12, then L0 must specify the "CR8-load exiting" and "CR8-store exiting" VM-execution controls in vmcs02. Failure to do so will give the L2 VM unrestricted read/write access to the hardware CR8. This fixes CVE-2017-12154. Signed-off-by: Jim Mattson Reviewed-by: David Hildenbrand Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -10271,6 +10271,11 @@ static int prepare_vmcs02(struct kvm_vcp if (exec_control & CPU_BASED_TPR_SHADOW) { vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, -1ull); vmcs_write32(TPR_THRESHOLD, vmcs12->tpr_threshold); + } else { +#ifdef CONFIG_X86_64 + exec_control |= CPU_BASED_CR8_LOAD_EXITING | + CPU_BASED_CR8_STORE_EXITING; +#endif } /*