CVE-2015-5307 kernel: kvm: guest to host DoS by triggering an infinite loop in microcode via #AC exception

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

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 Hello,

A guest to host DoS issue was found affecting various hypervisors. In that, a 
a guest can DoS the host by triggering an infinite stream of "alignment check" 
(#AC) exceptions. This causes the microcode to enter an infinite loop where 
the core never receives another interrupt. The host kernel panics due to this 
effect.

Reference:
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  -> https://bugzilla.redhat.com/show_bug.cgi?id=1277557

This issue was found by Mr Ben Serebrin of Google Inc.

Thank you.
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Prasad J Pandit / Red Hat Product Security Team
47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F

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