This is a note to let you know that I've just added the patch titled
kvm: nVMX: Don't allow L2 to access the hardware CR8
to the 4.13-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-don-t-allow-l2-to-access-the-hardware-cr8.patch
and it can be found in the queue-4.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 51aa68e7d57e3217192d88ce90fd5b8ef29ec94f Mon Sep 17 00:00:00 2001
From: Jim Mattson <jmattson@xxxxxxxxxx>
Date: Tue, 12 Sep 2017 13:02:54 -0700
Subject: kvm: nVMX: Don't allow L2 to access the hardware CR8
From: Jim Mattson <jmattson@xxxxxxxxxx>
commit 51aa68e7d57e3217192d88ce90fd5b8ef29ec94f upstream.
If L1 does not specify the "use TPR shadow" VM-execution control in
vmcs12, then L0 must specify the "CR8-load exiting" and "CR8-store
exiting" VM-execution controls in vmcs02. Failure to do so will give
the L2 VM unrestricted read/write access to the hardware CR8.
This fixes CVE-2017-12154.
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10271,6 +10271,11 @@ static int prepare_vmcs02(struct kvm_vcp
if (exec_control & CPU_BASED_TPR_SHADOW) {
vmcs_write64(VIRTUAL_APIC_PAGE_ADDR, -1ull);
vmcs_write32(TPR_THRESHOLD, vmcs12->tpr_threshold);
+ } else {
+#ifdef CONFIG_X86_64
+ exec_control |= CPU_BASED_CR8_LOAD_EXITING |
+ CPU_BASED_CR8_STORE_EXITING;
+#endif
}
/*
Patches currently in stable-queue which might be from jmattson@xxxxxxxxxx are
queue-4.13/kvm-nvmx-don-t-allow-l2-to-access-the-hardware-cr8.patch