From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755276Ab1ABHdx (ORCPT ); Sun, 2 Jan 2011 02:33:53 -0500 Received: from mail.windriver.com ([147.11.1.11]:37117 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754855Ab1ABHZj (ORCPT ); Sun, 2 Jan 2011 02:25:39 -0500 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Avi Kivity , Marcelo Tosatti , Paul Gortmaker Subject: [34-longterm 235/260] KVM: VMX: Fix host GDT.LIMIT corruption Date: Sun, 2 Jan 2011 02:18:51 -0500 Message-Id: <1293952756-15010-236-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.3.3 In-Reply-To: <1293952756-15010-1-git-send-email-paul.gortmaker@windriver.com> References: <1293952756-15010-1-git-send-email-paul.gortmaker@windriver.com> X-OriginalArrivalTime: 02 Jan 2011 07:24:27.0042 (UTC) FILETIME=[166A3020:01CBAA4E] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Avi Kivity commit 3444d7da1839b851eefedd372978d8a982316c36 upstream. vmx does not restore GDT.LIMIT to the host value, instead it sets it to 64KB. This means host userspace can learn a few bits of host memory. Fix by reloading GDTR when we load other host state. Signed-off-by: Avi Kivity Signed-off-by: Marcelo Tosatti Signed-off-by: Paul Gortmaker --- arch/x86/kvm/vmx.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 3c86c42..11db911 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -170,6 +170,7 @@ static u64 construct_eptp(unsigned long root_hpa); static DEFINE_PER_CPU(struct vmcs *, vmxarea); static DEFINE_PER_CPU(struct vmcs *, current_vmcs); static DEFINE_PER_CPU(struct list_head, vcpus_on_cpu); +static DEFINE_PER_CPU(struct desc_ptr, host_gdt); static unsigned long *vmx_io_bitmap_a; static unsigned long *vmx_io_bitmap_b; @@ -717,6 +718,7 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx) wrmsrl(MSR_KERNEL_GS_BASE, vmx->msr_host_kernel_gs_base); } #endif + load_gdt(&__get_cpu_var(host_gdt)); } static void vmx_load_host_state(struct vcpu_vmx *vmx) @@ -1218,6 +1220,8 @@ static int hardware_enable(void *garbage) ept_sync_global(); + store_gdt(&__get_cpu_var(host_gdt)); + return 0; } -- 1.7.3.3