CVE-2017-2583 Kernel: Kvm: vmx/svm potential privilege escalation inside guest

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

  Hello,

Linux kernel built with the Kernel-based Virtual Machine(CONFIG_KVM) support 
is vulnerable an incorrect segment selector(SS) value error. It could occur 
loading values into SS register in long mode.

A user/process inside guest could use this flaw to crash the guest resulting 
in DoS or potentially escalate their privileges inside guest.

Upstream patch:
---------------
  -> https://git.kernel.org/linus/33ab91103b3415e12457e3104f0e4517ce12d0f3

Reference:
----------
  -> https://bugzilla.redhat.com/show_bug.cgi?id=1414735

Note: On Intel CPUs it'd corrupt the guest state resulting in DoS; Whereas on
      AMD CPUs it could potentially escalate privileges inside guest.

This issue was discovered by Xiaohan Zhang of Huawei Inc.

'CVE-2017-2583' was assigned to this issue by Red Hat Inc.

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