Commit ee695f22 authored by Krish Sadhukhan's avatar Krish Sadhukhan Committed by Paolo Bonzini
Browse files

nSVM: Check addresses of MSR and IO permission maps 



According to section "Canonicalization and Consistency Checks" in APM vol 2,
the following guest state is illegal:

    "The MSR or IOIO intercept tables extend to a physical address that
     is greater than or equal to the maximum supported physical address."

Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarKrish Sadhukhan <krish.sadhukhan@oracle.com>
Message-Id: <20210412215611.110095-5-krish.sadhukhan@oracle.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 47903dc1

arch/x86/kvm/svm/nested.c

+22 −3
Original line number Diff line number Diff line
@@ -215,7 +215,19 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm) 
	return true;

}



static bool nested_vmcb_check_controls(struct vmcb_control_area *control)

/*

 * Bits 11:0 of bitmap address are ignored by hardware

 */

static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa, u32 size)

{

	u64 addr = PAGE_ALIGN(pa);



	return kvm_vcpu_is_legal_gpa(vcpu, addr) &&

	    kvm_vcpu_is_legal_gpa(vcpu, addr + size - 1);

}



static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu,

				       struct vmcb_control_area *control)

{

	if (CC(!vmcb_is_intercept(control, INTERCEPT_VMRUN)))

		return false;
@@ -226,6 +238,13 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control) 
	if (CC((control->nested_ctl & SVM_NESTED_CTL_NP_ENABLE) && !npt_enabled))

		return false;



	if (CC(!nested_svm_check_bitmap_pa(vcpu, control->msrpm_base_pa,

					   MSRPM_SIZE)))

		return false;

	if (CC(!nested_svm_check_bitmap_pa(vcpu, control->iopm_base_pa,

					   IOPM_SIZE)))

		return false;



	return true;

}
@@ -604,7 +623,7 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu) 
	nested_load_control_from_vmcb12(svm, &vmcb12->control);



	if (!nested_vmcb_valid_sregs(vcpu, &vmcb12->save) ||

	    !nested_vmcb_check_controls(&svm->nested.ctl)) {

	    !nested_vmcb_check_controls(vcpu, &svm->nested.ctl)) {

		vmcb12->control.exit_code    = SVM_EXIT_ERR;

		vmcb12->control.exit_code_hi = 0;

		vmcb12->control.exit_info_1  = 0;
@@ -1252,7 +1271,7 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu, 
		goto out_free;



	ret = -EINVAL;

	if (!nested_vmcb_check_controls(ctl))

	if (!nested_vmcb_check_controls(vcpu, ctl))

		goto out_free;



	/*