diff options
| author | Jim Mattson <jmattson@google.com> | 2017-09-12 13:02:54 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-09-15 14:05:46 +0200 |
| commit | 51aa68e7d57e3217192d88ce90fd5b8ef29ec94f (patch) | |
| tree | 96b602951ac8eb47d92e93180f98cd470e2b7877 /arch/x86/kvm/vmx.c | |
| parent | 488e32f1981e506976d666b3772d6ccc8b726fee (diff) | |
kvm: nVMX: Don't allow L2 to access the hardware CR8
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>
Diffstat (limited to 'arch/x86/kvm/vmx.c')
| -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 09204993a739..8e1ae716f938 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -10525,6 +10525,11 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, 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 } /* |