Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757352Ab0KSVv7 (ORCPT ); Fri, 19 Nov 2010 16:51:59 -0500 Received: from kroah.org ([198.145.64.141]:51778 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757307Ab0KSVp3 (ORCPT ); Fri, 19 Nov 2010 16:45:29 -0500 X-Mailbox-Line: From gregkh@clark.site Fri Nov 19 13:44:10 2010 Message-Id: <20101119214410.903294343@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 19 Nov 2010 13:42:58 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org, greg@kroah.com Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, avi@redhat.com, mtosatti@redhat.com Subject: [18/45] KVM: VMX: Fix host GDT.LIMIT corruption In-Reply-To: <20101119214439.GA26350@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1787 Lines: 55 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ 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: Greg Kroah-Hartman --- arch/x86/kvm/vmx.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -130,6 +130,7 @@ static u64 construct_eptp(unsigned long 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; @@ -690,6 +691,7 @@ static void __vmx_load_host_state(struct save_msrs(vmx->guest_msrs, vmx->save_nmsrs); load_msrs(vmx->host_msrs, vmx->save_nmsrs); reload_host_efer(vmx); + load_gdt(&__get_cpu_var(host_gdt)); } static void vmx_load_host_state(struct vcpu_vmx *vmx) @@ -1176,6 +1178,8 @@ static void hardware_enable(void *garbag asm volatile (ASM_VMX_VMXON_RAX : : "a"(&phys_addr), "m"(phys_addr) : "memory", "cc"); + + store_gdt(&__get_cpu_var(host_gdt)); } static void vmclear_local_vcpus(void) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/