RHBA-2015:0296 - Bug Fix Advisory

Topic

Updated kpatch packages that fix several bugs and add various enhancements are now available for Red Hat Enterprise Linux 7.

Description

The kpatch management tool provides a kernel patching infrastructure which
allows you to patch a running kernel without rebooting or restarting any
processes. The kpatch tool works at the function level for replacing old
functions with new functions using hot patch modules.

The kpatch package has been upgraded to upstream version 0.1.10, which provides
a number of bug fixes and enhancements over the previous version, most notable
of which are:

• Added support for the KPATCH_FORCE_UNSAFE patch macro.
• Added support for a new core module location in the /usr/lib/kpatch file.

(BZ#1090084)

This update also fixes the following bugs:

• Previously, using the "kpatch install" command failed because the kpatch

script had some missing dependencies in the dracut module. As a consequence,
loading a new patch module failed after reboot. The missing dependencies have
been added to the kpatch dracut module and "kpatch install" now works as
expected. (BZ#1170369)

• Previously, running the "kpatch unload" command with an unsupported parameter

returned a confusing warning message. With this update, using an invalid
parameter with the command now returns a help text with usage information.
(BZ#1104081)

In addition, this update adds the following enhancements:

• The kpatch interface now lists both loaded and installed patch modules by

modprobe name, rather than by file name. This makes the syntax more intuitive
for users who want to load and unload installed modules. (BZ#1133045)

• It is now possible to re-enable patch modules which depend on the

KPATCH_FORCE_UNSAFE macro. This ensures that the "kpatch load" and "kpatch
unload" commands always co-operate with the mentioned patch modules.
(BZ#1140268)

Users of kpatch are advised to upgrade to these updated package, which fixes
these bugs and adds these enhancements.

Solution

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

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64

Fixes

• BZ - 1104081 - `kpatch unload` gives confusing message with unsupported parameter
• BZ - 1133045 - Use default path for modules when loading it trough kpatch
• BZ - 1140268 - kpatch: support for re-enabling forced modules
• BZ - 1170369 - kpatch: "kpatch install" is broken due to missing dracut dependencies

CVEs

(none)

References

• http://www.redhat.com/security/updates/classification/#normal