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authorLadi Prosek <lprosek@redhat.com>2017-10-05 11:10:22 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2017-10-10 15:31:18 +0200
commitfd19d3b45164466a4adce7cbff448ba9189e1427 (patch)
tree1ff127f382ee34d24ef4f5a93828f7f8e69cb616 /arch/x86
parent8a5776a5f49812d29fe4b2d0a2d71675c3facf3f (diff)
downloadlinux-fd19d3b45164466a4adce7cbff448ba9189e1427.tar.bz2
KVM: nVMX: update last_nonleaf_level when initializing nested EPT
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>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/mmu.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 106d4a029a8a..3c25f20115bc 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4555,6 +4555,7 @@ void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly,
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);
}