Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.13 53/53] KVM: nVMX: update last_nonleaf_level when initializing nested EPT | Date | Mon, 16 Oct 2017 18:16:50 +0200 |
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4.13-stable review patch. If anyone has any objections, please let me know.
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From: Ladi Prosek <lprosek@redhat.com>
commit fd19d3b45164466a4adce7cbff448ba9189e1427 upstream.
The function updates context->root_level but didn't call update_last_nonleaf_level so the previous and potentially wrong value was used for page walks. For example, a zero value of last_nonleaf_level would allow a potential out-of-bounds access in arch/x86/mmu/paging_tmpl.h's walk_addr_generic function (CVE-2017-12188).
Fixes: 155a97a3d7c78b46cef6f1a973c831bc5a4f82bb Signed-off-by: Ladi Prosek <lprosek@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/kvm/mmu.c | 1 + 1 file changed, 1 insertion(+)
--- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -4459,6 +4459,7 @@ void kvm_init_shadow_ept_mmu(struct kvm_ update_permission_bitmask(vcpu, context, true); update_pkru_bitmask(vcpu, context, true); + update_last_nonleaf_level(vcpu, context); reset_rsvds_bits_mask_ept(vcpu, context, execonly); reset_ept_shadow_zero_bits_mask(vcpu, context, execonly); }
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