KVM: MMU: bail out pagewalk on kvm_read_guest error
Exit the guest pagetable walk loop if reading gpte failed. Otherwise its
possible to enter an endless loop processing the previous present pte.
Cc: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 58a0f1e..ede2131 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -150,7 +150,9 @@
walker->table_gfn[walker->level - 1] = table_gfn;
walker->pte_gpa[walker->level - 1] = pte_gpa;
- kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte));
+ if (kvm_read_guest(vcpu->kvm, pte_gpa, &pte, sizeof(pte)))
+ goto not_present;
+
trace_kvm_mmu_paging_element(pte, walker->level);
if (!is_present_gpte(pte))
