CVE-2017-12188 Kernel: KVM: MMU potential stack buffer overrun during page walks

[P J P <ppandit () redhat com>]

   Hello,

Linux kernel built with the KVM virtualisation support(CONFIG_KVM), with 
nested virtualisation(nVMX) feature enabled(nested=1), is vulnerable to a 
stack buffer overflow issue. It could occur while traversing guest page table 
entries to resolve guest virtual address(gva).

A L1 guest could use this flaw to crash the host kernel resulting in DoS. OR 
potentially execute arbitrary code on the host to gain access to the host 
system.

Upstream patch:
---------------
  -> https://www.spinics.net/lists/kvm/msg156651.html

Reference:
----------
  -> https://bugzilla.redhat.com/show_bug.cgi?id=1500380

'CVE-2017-12188' assigned by Red Hat Inc.

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
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