This is a note to let you know that I've just added the patch titled
KVM: nVMX: update last_nonleaf_level when initializing nested EPT
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kvm-nvmx-update-last_nonleaf_level-when-initializing-nested-ept.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fd19d3b45164466a4adce7cbff448ba9189e1427 Mon Sep 17 00:00:00 2001
From: Ladi Prosek <lprosek@xxxxxxxxxx>
Date: Thu, 5 Oct 2017 11:10:22 +0200
Subject: KVM: nVMX: update last_nonleaf_level when initializing nested EPT
From: Ladi Prosek <lprosek@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 1 +
1 file changed, 1 insertion(+)
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4169,6 +4169,7 @@ 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);
}
Patches currently in stable-queue which might be from lprosek@xxxxxxxxxx are
queue-4.9/kvm-nvmx-update-last_nonleaf_level-when-initializing-nested-ept.patch
queue-4.9/kvm-mmu-always-terminate-page-walks-at-level-1.patch