RHBA-2013:1668 - Bug Fix Advisory

Topic

Updated microcode_ctl packages that fix one bug and add one enhancement are now
available for Red Hat Enterprise Linux 6.

Description

The microcode_ctl packages provide utility code and microcode data to assist the
kernel in updating the CPU microcode at system boot time. This microcode
supports all current x86-based, Intel 64-based, and AMD64-based CPU models. It
takes advantage of the mechanism built-in to Linux that allows microcode to be
updated after system boot. When loaded, the updated microcode corrects the
behavior of various processors, as described in processor specification updates
issued by Intel and AMD for those processors.

This update fixes the following bug:

• Previously, the microcode_ctl utility did not detect if it was running in a

virtual machine and attempted to install the CPU microcode updates. This
behavior caused several errors to be returned in the kernel ring buffer. The
underlying source code has been modified and microcode_ctl no longer tries to
update the CPU microcode in the described scenario. (BZ#1000317)

In addition, this update adds the following enhancement:

• The Intel CPU microcode file has been updated to version 20130906. (BZ#915957,

BZ#1005606)

All users of microcode_ctl are advised to upgrade to these updated packages,
which fix this bug and add this enhancement. Note: a system reboot is
necessary for this update to take effect.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/site/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386

Fixes

• BZ - 1000317 - microcode update should be skipped in virtualized environment

CVEs

(none)

References

(none)