CVE Request -- kernel: tight loop and no preemption can cause system stall

[Petr Matousek <pmatouse () redhat com>]

A tight loop in user level process isn't preempted unless a realtime
process is woken up on the cpu.  Some important kernel threads such as
events/*, kblockd/* can be blocked by the process, and the machine
stalls.

Unprivileged local user could use this flaw to DoS the system.

Upstream commit:
f26f9aff6aaf67e9a430d16c266f91b13a5bff64

Reference:
https://lkml.org/lkml/2010/11/20/212
https://bugzilla.redhat.com/show_bug.cgi?id=769711

Thanks,
-- 
Petr Matousek / Red Hat Security Response Team