RHBA-2013:1539 - Bug Fix Advisory

Topic

Updated hypervkvpd packages that fix several bugs are now available for Red Hat
Enterprise Linux 6.

Description

The hypervkvpd packages contain hypervkvpd, the guest Hyper-V Key-Value Pair
(KVP) daemon. Using VMbus, hypervkvpd passes basic information to the host. The
information includes guest IP address, fully qualified domain name, operating
system name, and operating system release number. An IP injection functionality
enables the user to change the IP address of a guest from the host via the
hypervkvpd daemon.

This update fixes the following bugs:

• Previously, the hypervkvpd service registered to two netlink multicast groups,

one of which was used by the cgred service. When hypervkvpd received a netlink
message, it was interpreted blindly as its own. As a consequence, hypervkvpd
terminated unexpectedly with a segmentation fault. After this update, hypervkvpd
now registers only to its own netlink multicast group and verifies the type of
the incoming netlink message. Using hypervkvpd when the cgred service is running
no longer leads to a segmentation fault. (BZ#920032)

• Prior to this update, the hypervkvpd init script did not check if Hyper-V

driver modules were loaded into the kernel. If hypervkvpd was installed, it
started automatically on system boot, even if the system was not running as a
guest machine on a Hyper-V hypervisor. Verification has been added to the
hypervkvpd init script to determine whether Hyper-V driver modules are loaded
into the kernel. As a result, if the modules are not loaded into the kernel,
hypervkvpd now does not start, but displays a message that proper driver modules
are not loaded. (BZ#962565)

• Previously, hypervkvpd was not built with sufficiently secure compiler

options, which could, consequently, make the compiled code vulnerable. The
hypervkvpd daemon has been built with full read-only relocation (RELRO) and
position-independent executable (PIE) flags. As a result, the compiled code is
more secure and better guarded against possible buffer overflows. (BZ#977861)

• When using the Get-VMNetworkAdapter command to query a virtual machine

network adapter, each subnet string has to be separated by a semicolon.
Due to a bug in the IPv6 subnet enumeration code, the IPv6 addresses
were not listed. A patch has been applied, and the IPv6 subnet
enumeration now works as expected. (BZ#983851)

Users of hypervkvpd are advised to upgrade to these updated packages, which fix
these bugs. After updating the hypervkvpd packages, rebooting all guest machines
is recommended, otherwise the Microsoft Windows server with Hyper-V might not be
able to get information from these guest machines.

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
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386

Fixes

• BZ - 920032 - hypervkvpd segfault when cgred is running
• BZ - 965944 - [Hyper-V][CoverityScan][RHEL6.5]Unchecked_value, null returns and resource leak
• BZ - 978300 - [Hyper-V][RHEL6.5]Failed to start the hypervkvpd service with error "Hyper-V drivers are not loaded"
• BZ - 983851 - hypervkvpd: Fix a bug in IPV6 subnet enumeration

CVEs

(none)

References

(none)