From a43593c96d220610246f4de55ce25d1b8cd8344b Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 10 Mar 2023 11:10:56 -0500 Subject: [PATCH] KVM: nVMX: add missing consistency checks for CR0 and CR4 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 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx/nested.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index d3a8ee0ef988a..cd96c31fe2bb4 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2779,7 +2779,7 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, u32 *exit_qual) { - bool ia32e; + bool ia32e = !!(vmcs12->vm_entry_controls & VM_ENTRY_IA32E_MODE); *exit_qual = ENTRY_FAIL_DEFAULT; @@ -2796,6 +2796,13 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu, 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: @@ -2807,7 +2814,6 @@ static int nested_vmx_check_guest_state(struct kvm_vcpu *vcpu, */ 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) && -- 2.39.5