Commit b1bd9caf authored by Felix Wilhelm's avatar Felix Wilhelm Committed by Greg Kroah-Hartman

kvm: nVMX: Enforce cpl=0 for VMX instructions

commit 727ba748 upstream.

VMX instructions executed inside a L1 VM will always trigger a VM exit
even when executed with cpl 3. This means we must perform the
privilege check in software.

Fixes: 70f3aac9("kvm: nVMX: Remove superfluous VMX instruction fault checks")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarFelix Wilhelm <fwilhelm@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3d2f0339
......@@ -7399,6 +7399,12 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
return 1;
}
/* CPL=0 must be checked manually. */
if (vmx_get_cpl(vcpu)) {
kvm_queue_exception(vcpu, UD_VECTOR);
return 1;
}
if (vmx->nested.vmxon) {
nested_vmx_failValid(vcpu, VMXERR_VMXON_IN_VMX_ROOT_OPERATION);
return kvm_skip_emulated_instruction(vcpu);
......@@ -7458,6 +7464,11 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
*/
static int nested_vmx_check_permission(struct kvm_vcpu *vcpu)
{
if (vmx_get_cpl(vcpu)) {
kvm_queue_exception(vcpu, UD_VECTOR);
return 0;
}
if (!to_vmx(vcpu)->nested.vmxon) {
kvm_queue_exception(vcpu, UD_VECTOR);
return 0;
......@@ -7790,7 +7801,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
if (get_vmx_mem_address(vcpu, exit_qualification,
vmx_instruction_info, true, &gva))
return 1;
/* _system ok, as hardware has verified cpl=0 */
/* _system ok, nested_vmx_check_permission has verified cpl=0 */
kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, gva,
&field_value, (is_long_mode(vcpu) ? 8 : 4), NULL);
}
......@@ -7933,7 +7944,7 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu)
if (get_vmx_mem_address(vcpu, exit_qualification,
vmx_instruction_info, true, &vmcs_gva))
return 1;
/* ok to use *_system, as hardware has verified cpl=0 */
/* *_system ok, nested_vmx_check_permission has verified cpl=0 */
if (kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, vmcs_gva,
(void *)&to_vmx(vcpu)->nested.current_vmptr,
sizeof(u64), &e)) {
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment