From 493821093f18655d39f16e31264c00b022640701 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti <mtosatti@redhat.com> Date: Thu, 14 Jan 2010 17:41:27 -0200 Subject: KVM: MMU: bail out pagewalk on kvm_read_guest error commit a6085fbaf65ab09bfb5ec8d902d6d21680fe1895 upstream. Exit the guest pagetable walk loop if reading gpte failed. Otherwise its possible to enter an endless loop processing the previous present pte. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- arch/x86/kvm/paging_tmpl.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 85e12cd6fb4..5fa33255348 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -150,7 +150,9 @@ walk: 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)) -- cgit v1.2.3-18-g5258