An information leakage issue was found in the way Linux kernel's KVM hypervisor
handled page fault exception while emulating instructions like VMXON, VMCLEAR,
VMPTRLD, VMWRITE with memory address as an operand. It occurs if the operand is
an mmio address, as the returned exception object holds uninitialised stack memory
A guest user/process could use this flaw to leak host's stack memory contents
to a guest.
It affects only Intel processors and only when nested virtualization is
Name: Felix Wilhelm (Google)
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1673686]
This issue does not affect the version of the kernel package as shipped with Red Hat Enterprise Linux 5, 6, and Red Hat Enterprise MRG 2.
This issue affects the versions of Linux kernel as shipped with Red Hat Enterprise Linux 7. Future kernel updates for Red Hat Enterprise Linux 7 may address this issue.
Note:- Impact on Red Hat Enterprise Linux 7 kernel is limited, as it requires that nested virtualization feature is enabled on a system. Nested Virtualization feature is available only as - Technology Preview.