| | 1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
| | 2 | From: Felix Wilhelm <fwilhelm@google.com> |
| | 3 | Date: Mon, 11 Jun 2018 09:43:44 +0200 |
| | 4 | Subject: [PATCH] kvm: nVMX: Enforce cpl=0 for VMX instructions |
| | 5 | |
| | 6 | VMX instructions executed inside a L1 VM will always trigger a VM exit |
| | 7 | even when executed with cpl 3. This means we must perform the |
| | 8 | privilege check in software. |
| | 9 | |
| | 10 | Fixes: 70f3aac964ae("kvm: nVMX: Remove superfluous VMX instruction fault checks") |
| | 11 | Cc: stable@vger.kernel.org |
| | 12 | Signed-off-by: Felix Wilhelm <fwilhelm@google.com> |
| | 13 | Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
| | 14 | Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com> |
| | 15 | --- |
| | 16 | arch/x86/kvm/vmx.c | 15 +++++++++++++-- |
| | 17 | 1 file changed, 13 insertions(+), 2 deletions(-) |
| | 18 | |
| | 19 | diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c |
| | 20 | index 54980817194a..b2d75b59b6e5 100644 |
| | 21 | --- a/arch/x86/kvm/vmx.c |
| | 22 | +++ b/arch/x86/kvm/vmx.c |
| | 23 | @@ -7180,6 +7180,12 @@ static int handle_vmon(struct kvm_vcpu *vcpu) |
| | 24 | return 1; |
| | 25 | } |
| | 26 | |
| | 27 | + /* CPL=0 must be checked manually. */ |
| | 28 | + if (vmx_get_cpl(vcpu)) { |
| | 29 | + kvm_queue_exception(vcpu, UD_VECTOR); |
| | 30 | + return 1; |
| | 31 | + } |
| | 32 | + |
| | 33 | if (vmx->nested.vmxon) { |
| | 34 | nested_vmx_failValid(vcpu, VMXERR_VMXON_IN_VMX_ROOT_OPERATION); |
| | 35 | return kvm_skip_emulated_instruction(vcpu); |
| | 36 | @@ -7239,6 +7245,11 @@ static int handle_vmon(struct kvm_vcpu *vcpu) |
| | 37 | */ |
| | 38 | static int nested_vmx_check_permission(struct kvm_vcpu *vcpu) |
| | 39 | { |
| | 40 | + if (vmx_get_cpl(vcpu)) { |
| | 41 | + kvm_queue_exception(vcpu, UD_VECTOR); |
| | 42 | + return 0; |
| | 43 | + } |
| | 44 | + |
| | 45 | if (!to_vmx(vcpu)->nested.vmxon) { |
| | 46 | kvm_queue_exception(vcpu, UD_VECTOR); |
| | 47 | return 0; |
| | 48 | @@ -7577,7 +7588,7 @@ static int handle_vmread(struct kvm_vcpu *vcpu) |
| | 49 | if (get_vmx_mem_address(vcpu, exit_qualification, |
| | 50 | vmx_instruction_info, true, &gva)) |
| | 51 | return 1; |
| | 52 | - /* _system ok, as hardware has verified cpl=0 */ |
| | 53 | + /* _system ok, nested_vmx_check_permission has verified cpl=0 */ |
| | 54 | kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, gva, |
| | 55 | &field_value, (is_long_mode(vcpu) ? 8 : 4), NULL); |
| | 56 | } |
| | 57 | @@ -7720,7 +7731,7 @@ static int handle_vmptrst(struct kvm_vcpu *vcpu) |
| | 58 | if (get_vmx_mem_address(vcpu, exit_qualification, |
| | 59 | vmx_instruction_info, true, &vmcs_gva)) |
| | 60 | return 1; |
| | 61 | - /* ok to use *_system, as hardware has verified cpl=0 */ |
| | 62 | + /* *_system ok, nested_vmx_check_permission has verified cpl=0 */ |
| | 63 | if (kvm_write_guest_virt_system(&vcpu->arch.emulate_ctxt, vmcs_gva, |
| | 64 | (void *)&to_vmx(vcpu)->nested.current_vmptr, |
| | 65 | sizeof(u64), &e)) { |
projects / pve-kernel.git / blame_incremental