The kernel-rt packages contain the Linux kernel, the core of any Linux operating system.
This update provides a build of the kernel-rt package for MRG 2.3, which is layered on Red Hat Enterprise Linux 6.
Descriptions of the security fixes provided in this advisory can be viewed at The bug fixes provided in this advisory are documented below:

Bug Fixes

Portions of buildID were missing from vmlinux and vDSO images, consequently it was not possible to use systemtap or make annotations in perf. This update sets the AFTER_LINK variable which gets the buildID components into the final emdedded images. Systemtap and perf now work as expected.
A race condition in the bonding driver caused the system to be unresponsive. This update adds a synchronize_net() in netdev_rx_handler_unregister(), ensuring that a rcuprotected reader is guaranteed to see a non NULL rx_handler_data, thus preventing the race condition in the bonding driver and restoring system responsiveness.
Cgroup configurations have been enabled in the Realtime kernel version 3.6, so its services and capabilities match Red Hat Enterprise Linux more closely.
The DEFAULTKERNEL parameter was not modified in /etc/sysconfig/kernel for the kernel-rt package. Consequently, upgrading any non-Realtime kernels reset the default kernel to a non-Realtime kernel. All MRG Realtime kernel variants are now classified as 'kernel-rt' when installing or upgrading, so upgrades of non-Realtime kernels do not reset the default kernel, and the Realtime kernel remains the default as expected.
Previously the NO_HZ option was enabled by default, which could have adverse effects on system performance. The NO_HZ option is now disabled by default to improve performance, but users can still enable it if necessary using the CONFIG_NO_HZ boot option.
Users are advised upgrade to these updated kernel-rt packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.