Messages in this thread Patch in this message | | | Date | Tue, 27 Feb 2024 18:41:46 -0800 | Subject | [PATCH 15/16] KVM: x86/mmu: Initialize kvm_page_fault's pfn and hva to error values | From | Sean Christopherson <> |
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Explicitly set "pfn" and "hva" to error values in kvm_mmu_do_page_fault() to harden KVM against using "uninitialized" values. In quotes because the fields are actually zero-initialized, and zero is a legal value for both page frame numbers and virtual addresses. E.g. failure to set "pfn" prior to creating an SPTE could result in KVM pointing at physical address '0', which is far less desirable than KVM generating a SPTE with reserved PA bits set and thus effectively killing the VM.
Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/mmu/mmu_internal.h | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 74736d517e74..67e32dec9424 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -307,6 +307,9 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, .req_level = PG_LEVEL_4K, .goal_level = PG_LEVEL_4K, .is_private = err & PFERR_PRIVATE_ACCESS, + + .pfn = KVM_PFN_ERR_FAULT, + .hva = KVM_HVA_ERR_BAD, }; int r; -- 2.44.0.278.ge034bb2e1d-goog
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