lkml.org 
[lkml]   [2024]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
Subject[PATCH 15/16] KVM: x86/mmu: Initialize kvm_page_fault's pfn and hva to error values
From
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

\
 
 \ /
  Last update: 2024-05-27 15:25    [W:1.567 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site