This is a note to let you know that I've just added the patch titled
KVM: nVMX: add missing consistency checks for CR0 and CR4
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-nvmx-add-missing-consistency-checks-for-cr0-and-cr4.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 112e66017bff7f2837030f34c2bc19501e9212d5 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Date: Fri, 10 Mar 2023 11:10:56 -0500
Subject: KVM: nVMX: add missing consistency checks for CR0 and CR4
From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
commit 112e66017bff7f2837030f34c2bc19501e9212d5 upstream.
The effective values of the guest CR0 and CR4 registers may differ from
those included in the VMCS12. In particular, disabling EPT forces
CR4.PAE=1 and disabling unrestricted guest mode forces CR0.PG=CR0.PE=1.
Therefore, checks on these bits cannot be delegated to the processor
and must be performed by KVM.
Reported-by: Reima ISHII <ishiir@xxxxxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3021,7 +3021,7 @@ static int nested_vmx_check_guest_state(
struct vmcs12 *vmcs12,
enum vm_entry_failure_code *entry_failure_code)
{
- bool ia32e;
+ bool ia32e = !!(vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE);
*entry_failure_code = ENTRY_FAIL_DEFAULT;
@@ -3047,6 +3047,13 @@ static int nested_vmx_check_guest_state(
vmcs12->guest_ia32_perf_global_ctrl)))
return -EINVAL;
+ if (CC((vmcs12->guest_cr0 & (X86_CR0_PG | X86_CR0_PE)) == X86_CR0_PG))
+ return -EINVAL;
+
+ if (CC(ia32e && !(vmcs12->guest_cr4 & X86_CR4_PAE)) ||
+ CC(ia32e && !(vmcs12->guest_cr0 & X86_CR0_PG)))
+ return -EINVAL;
+
/*
* If the load IA32_EFER VM-entry control is 1, the following checks
* are performed on the field for the IA32_EFER MSR:
@@ -3058,7 +3065,6 @@ static int nested_vmx_check_guest_state(
*/
if (to_vmx(vcpu)->nested.nested_run_pending &&
(vmcs12->vm_entry_controls & VM_ENTRY_LOAD_IA32_EFER)) {
- ia32e = (vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE) != 0;
if (CC(!kvm_valid_efer(vcpu, vmcs12->guest_ia32_efer)) ||
CC(ia32e != !!(vmcs12->guest_ia32_efer & EFER_LMA)) ||
CC(((vmcs12->guest_cr0 & X86_CR0_PG) &&
Patches currently in stable-queue which might be from pbonzini@xxxxxxxxxx are
queue-6.2/kvm-svm-modify-avic-gatag-to-support-max-number-of-512-vcpus.patch
queue-6.2/kvm-svm-fix-a-benign-off-by-one-bug-in-avic-physical-table-mask.patch
queue-6.2/kvm-nvmx-add-missing-consistency-checks-for-cr0-and-cr4.patch
