RHBA-2013:1856 - Bug Fix Advisory

Topic

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

Description

The libvirt library is a C API for managing and interacting with the
virtualization capabilities of Linux and other operating systems. In addition,
libvirt provides tools for remote management of virtualized systems.

This update fixes the following bugs:

• When de-registering the last callback for an event, an improper variable was

used for the de-registration of the event itself. As a consequence, the
following error message was returned, even though the code was used properly:

Error "libvirt: XML-RPC error : internal error: domain event 0 not
registered"

With this update, the underlying source code has been changed to use the proper
variable. As a result, the de-registration of the last callback for any event
executes successfully, without returning an error message. (BZ#1038814)

• Previously, the libvirt python bindings for querying block job status could

not distinguish between returning an error and no status available. As a
consequence, the code that was polling for the completion of a block job had to
deal with a python exception, and could not distinguish it from an actual error.
After this update, the bindings now successfully determine if there is no job
and return an empty dictionary in this case. As a result, the bindings can be
used more reliably when managing block jobs. (BZ#1038815)

• When two threads were working over the same domain, the first thread started a

domain and the second attempted to destroy it. In such scenarios, a race
condition could occur, causing a domain to disappear in both threads, and
leaving the start daemon access freed of memory. As a consequence, the daemon
terminated unexpectedly. To fix this bug, the critical section has been guarded
by incrementing the reference counter of the domain. Whenever the domain is
destroyed, the startup thread still holds the last reference which gets
decremented once the startup process finishes. As a result, the daemon no longer
crashes. (BZ#1038816)

• Previously, when the user did not specify a model for the SCSI

controller or did not specify a controller at all, libvirt failed to
find a suitable SCSI controller model because it did not try the
virtio-scsi model. This bug has been fixed and libvirt now checks virtio-scsi
when searching for a usable model. This also allows for a dynamic addition of a
SCSI controller to a running domain. (BZ#1040141)

Users of libvirt are advised to upgrade to these updated packages, which fix
these bugs. After installing the updated packages, libvirtd will be restarted
automatically.

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 for x86_64 - Extended Update Support 6.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 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 IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.5 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.5 ppc64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Virtualization 3 for RHEL 6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 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 for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 6.5 x86_64
• Red Hat Enterprise Linux Server - AUS 6.5 x86_64
• Red Hat Enterprise Linux Server - TUS 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 1038814 - regression in event deregistration
• BZ - 1038815 - blockJobInfo python API run success but return None
• BZ - 1038816 - libvirtd crash when create/destroy VM repeatedly

CVEs

(none)

References

(none)