[PATCH 2/5 v5] nSVM: Check addresses of MSR and IO permission maps

[Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>]

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: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
---
 arch/x86/kvm/svm/nested.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 35891d9a1099..8d04e69db038 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -231,7 +231,15 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu)
 	return true;
 }
 
-static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
+static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa,
+				       u32 size)
+{
+	u64 last_pa = PAGE_ALIGN(pa) + size - 1;
+	return (kvm_vcpu_is_legal_gpa(vcpu, last_pa));
+}
+
+static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
+				       struct vmcb_control_area *control)
 {
 	if ((vmcb_is_intercept(control, INTERCEPT_VMRUN)) == 0)
 		return false;
@@ -243,12 +251,18 @@ static bool nested_vmcb_check_controls(struct vmcb_control_area *control)
 	    !npt_enabled)
 		return false;
 
+	if (!nested_svm_check_bitmap_pa(vcpu, control->msrpm_base_pa,
+	    MSRPM_ALLOC_SIZE))
+		return false;
+	if (!nested_svm_check_bitmap_pa(vcpu, control->iopm_base_pa,
+	    IOPM_ALLOC_SIZE - PAGE_SIZE + 1))
+		return false;
+
 	return true;
 }
 
-static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
+static bool nested_vmcb_checks(struct kvm_vcpu *vcpu, struct vmcb *vmcb12)
 {
-	struct kvm_vcpu *vcpu = &svm->vcpu;
 	bool vmcb12_lma;
 
 	if ((vmcb12->save.efer & EFER_SVME) == 0)
@@ -268,10 +282,10 @@ static bool nested_vmcb_checks(struct vcpu_svm *svm, struct vmcb *vmcb12)
 		    kvm_vcpu_is_illegal_gpa(vcpu, vmcb12->save.cr3))
 			return false;
 	}
-	if (!kvm_is_valid_cr4(&svm->vcpu, vmcb12->save.cr4))
+	if (!kvm_is_valid_cr4(vcpu, vmcb12->save.cr4))
 		return false;
 
-	return nested_vmcb_check_controls(&vmcb12->control);
+	return nested_vmcb_check_controls(vcpu, &vmcb12->control);
 }
 
 static void load_nested_vmcb_control(struct vcpu_svm *svm,
@@ -515,7 +529,7 @@ int nested_svm_vmrun(struct vcpu_svm *svm)
 	if (WARN_ON_ONCE(!svm->nested.initialized))
 		return -EINVAL;
 
-	if (!nested_vmcb_checks(svm, vmcb12)) {
+	if (!nested_vmcb_checks(&svm->vcpu, vmcb12)) {
 		vmcb12->control.exit_code    = SVM_EXIT_ERR;
 		vmcb12->control.exit_code_hi = 0;
 		vmcb12->control.exit_info_1  = 0;
@@ -1191,7 +1205,7 @@ 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;
 
 	/*
-- 
2.27.0