The Linux kernel before 2.6.37 does not properly implement a certain clock-update optimization, which allows local users to cause a denial of service (system hang) via an application that executes code in a loop.
ftp.osuosl.org/pub/linux/kernel/v2.6/ChangeLog-2.6.37
git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=f26f9aff6aaf67e9a430d16c266f91b13a5bff64
www.openwall.com/lists/oss-security/2011/12/21/6
bugzilla.redhat.com/show_bug.cgi?id=769711
github.com/torvalds/linux/commit/f26f9aff6aaf67e9a430d16c266f91b13a5bff64