From f3310e622f77979f13a36f6bfaf0252eecc7b9f6 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 27 Feb 2024 18:41:46 -0800 Subject: [PATCH] KVM: x86/mmu: Initialize kvm_page_fault's pfn and hva to error values 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 Reviewed-by: Kai Huang Message-ID: <20240228024147.41573-16-seanjc@google.com> Signed-off-by: Paolo Bonzini --- 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 dfd9ff3836634..ce2fcd19ba6be 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; -- 2.30.2