From: Sean Christopherson seanjc@google.com
commit 886bbcc7a523b8d4fac60f1015d2e0fcad50db82 upstream.
Check CR3 for an invalid GPA even if the vCPU isn't in long mode. For bigger emulation flows, notably RSM, the vCPU mode may not be accurate if CR0/CR4 are loaded after CR3. For MOV CR3 and similar flows, the caller is responsible for truncating the value.
Fixes: 660a5d517aaa ("KVM: x86: save/load state on SMM switch") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson seanjc@google.com Message-Id: 20210422022128.3464144-3-seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/x86/kvm/x86.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
--- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1072,10 +1072,15 @@ int kvm_set_cr3(struct kvm_vcpu *vcpu, u return 0; }
- if (is_long_mode(vcpu) && kvm_vcpu_is_illegal_gpa(vcpu, cr3)) + /* + * Do not condition the GPA check on long mode, this helper is used to + * stuff CR3, e.g. for RSM emulation, and there is no guarantee that + * the current vCPU mode is accurate. + */ + if (kvm_vcpu_is_illegal_gpa(vcpu, cr3)) return 1; - else if (is_pae_paging(vcpu) && - !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)) + + if (is_pae_paging(vcpu) && !load_pdptrs(vcpu, vcpu->arch.walk_mmu, cr3)) return 1;
kvm_mmu_new_pgd(vcpu, cr3, skip_tlb_flush, skip_tlb_flush);