The software described in this documentation is either in Extended Support or Sustaining Support. See https://www.oracle.com/us/support/library/enterprise-linux-support-policies-069172.pdf for more information.
Oracle recommends that you upgrade the software described by this documentation as soon as possible.

1.2 Unbreakable Enterprise Kernel Release 2

The Unbreakable Enterprise Kernel Release 2 (UEK R2) is based on the upstream kernel 3.0.36 stable source tree.

The Unbreakable Enterprise Kernel supports a wide range of hardware and devices. In close cooperation with hardware and storage vendors, a number of device drivers have been updated by Oracle in the 2.6.39-400 kernel. For details, see the Oracle Linux Unbreakable Enterprise Kernel Release 2 Quarterly Update 5 Release Notes.