diff options
| author | Jim Mattson <jmattson@google.com> | 2017-09-12 13:02:54 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-10-05 09:44:03 +0200 |
| commit | 86ef97b2dfd504fbc65f6b244a422db0c1b15797 (patch) | |
| tree | 76d9c5e3514b9c968af808a075c3dc86a3826f16 | |
| parent | 3d4213fac7d10e72859112c9100d8015ce442a3a (diff) | |
kvm: nVMX: Don't allow L2 to access the hardware CR8
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 <jmattson@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 53862744c0db..a29f5452f83d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -10001,6 +10001,11 @@ static void prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12) vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, page_to_phys(vmx->nested.virtual_apic_page)); 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 } if (cpu_has_vmx_msr_bitmap() && |