-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                               ESB-2009.1621
                 Moderate: kvm security and bug fix update
                             10 December 2009

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           kvm
Publisher:         Red Hat
Operating System:  Red Hat Enterprise Linux WS/Desktop 5
                   Red Hat Enterprise Linux Server 5
                   Linux variants
Impact/Access:     Denial of Service -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2009-4031  

Original Bulletin: 
   https://rhn.redhat.com/errata/RHSA-2009-1659.html

Comment: This advisory references vulnerabilities in products which run on 
         platforms other than Red Hat. It is recommended that administrators
         running kvm check for an updated version of the software for their 
         operating system.

- --------------------------BEGIN INCLUDED TEXT--------------------

- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

=====================================================================
                   Red Hat Security Advisory

Synopsis:          Moderate: kvm security and bug fix update
Advisory ID:       RHSA-2009:1659-01
Product:           Red Hat Enterprise Linux
Advisory URL:      https://rhn.redhat.com/errata/RHSA-2009-1659.html
Issue date:        2009-12-09
CVE Names:         CVE-2009-4031 
=====================================================================

1. Summary:

Updated kvm packages that fix one security issue and several bugs are now
available for Red Hat Enterprise Linux 5.

This update has been rated as having moderate security impact by the Red
Hat Security Response Team.

2. Relevant releases/architectures:

RHEL Desktop Multi OS (v. 5 client) - x86_64
RHEL Virtualization (v. 5 server) - x86_64

3. Description:

KVM (Kernel-based Virtual Machine) is a full virtualization solution for
Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built for
the standard Red Hat Enterprise Linux kernel.

On x86 platforms, the do_insn_fetch() function did not limit the amount of
instruction bytes fetched per instruction. Users in guest operating systems
could leverage this flaw to cause large latencies on SMP hosts that could
lead to a local denial of service on the host operating system. This
update fixes this issue by imposing the architecturally-defined 15 byte
length limit for instructions. (CVE-2009-4031)

This update also fixes the following bugs:

* performance problems occurred when using the qcow2 image format with the
qemu-kvm -drive "cache=none" option (the default setting when not specified
otherwise). This could cause guest operating system installations to take
hours. With this update, performance patches have been backported so that
using the qcow2 image format with the "cache=none" option no longer causes
performance issues. (BZ#520693)

* when using the virtual vm8086 mode, bugs in the emulated hardware task
switching implementation may have, in some situations, caused older guest
operating systems to malfunction. (BZ#532031)

* Windows Server 2003 guests (32-bit) with more than 4GB of memory may have
crashed during reboot when using the default qemu-kvm CPU settings.
(BZ#532043)

* with Red Hat Enterprise Virtualization, guests continued to run after
encountering disk read errors. This could have led to their file systems
becoming corrupted (but not the host's), notably in environments that use
networked storage. With this update, the qemu-kvm -drive "werror=stop"
option now applies not only to write errors but also to read errors: When
using this option, guests will pause on disk read and write errors.

By default, guests managed by Red Hat Enterprise Virtualization use the
"werror=stop" option. This option is not used by default for guests managed
by libvirt. (BZ#537334, BZ#540406)

* the para-virtualized block driver (virtio-blk) silently ignored read
errors when accessing disk images. With this update, the driver correctly
signals the read error to the guest. (BZ#537334)

All KVM users should upgrade to these updated packages, which contain
backported patches to resolve these issues. Note: The procedure in the
Solution section must be performed before this update will take effect.

4. Solution:

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

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

The following procedure must be performed before this update will take
effect:

1) Stop all KVM guest virtual machines.

2) Either reboot the hypervisor machine or, as the root user, remove (using
"modprobe -r [module]") and reload (using "modprobe [module]") all of the
following modules which are currently running (determined using "lsmod"):
kvm, ksm, kvm-intel or kvm-amd.

3) Restart the KVM guest virtual machines.

5. Bugs fixed (http://bugzilla.redhat.com/):

532031 - KVM does not implement proper support for hardware task linking when using vm8086 mode
532043 - qemu aborted when restart 32bitwin23k with more than 4G mem in intel host.
537334 - O/S Filesystem Corruption with RHEL-5.4 on a RHEV Guest
540406 - RHEL5.4 VM image corruption with an IDE v-disk
541160 - CVE-2009-4031 kernel: KVM: x86 emulator: limit instructions to 15 bytes

6. Package List:

RHEL Desktop Multi OS (v. 5 client):

Source:
ftp://ftp.redhat.com/pub/redhat/linux/enterprise/5Client/en/os/SRPMS/kvm-83-105.el5_4.13.src.rpm

x86_64:
kmod-kvm-83-105.el5_4.13.x86_64.rpm
kvm-83-105.el5_4.13.x86_64.rpm
kvm-debuginfo-83-105.el5_4.13.x86_64.rpm
kvm-qemu-img-83-105.el5_4.13.x86_64.rpm
kvm-tools-83-105.el5_4.13.x86_64.rpm

RHEL Virtualization (v. 5 server):

Source:
ftp://ftp.redhat.com/pub/redhat/linux/enterprise/5Server/en/os/SRPMS/kvm-83-105.el5_4.13.src.rpm

x86_64:
kmod-kvm-83-105.el5_4.13.x86_64.rpm
kvm-83-105.el5_4.13.x86_64.rpm
kvm-debuginfo-83-105.el5_4.13.x86_64.rpm
kvm-qemu-img-83-105.el5_4.13.x86_64.rpm
kvm-tools-83-105.el5_4.13.x86_64.rpm

These packages are GPG signed by Red Hat for security.  Our key and 
details on how to verify the signature are available from
https://www.redhat.com/security/team/key/#package

7. References:

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-4031
http://www.redhat.com/security/updates/classification/#moderate

8. Contact:

The Red Hat security contact is <secalert@redhat.com>.  More contact
details at https://www.redhat.com/security/team/contact/

Copyright 2009 Red Hat, Inc.
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.4 (GNU/Linux)

iD8DBQFLH9EXXlSAg2UNWIIRAv8oAJ9Q0eSSPCDZPXVjH6R4lwDjJGM/NwCfe126
QRjKPSU1gAQ8mEBAN03qm70=
=Y+Un
- -----END PGP SIGNATURE-----

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        http://www.auscert.org.au/render.html?cid=1980

If you believe that your computer system has been compromised or attacked in 
any way, we encourage you to let us know by completing the secure National IT 
Incident Reporting Form at:

        http://www.auscert.org.au/render.html?it=3192

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967

iD8DBQFLIEzaNVH5XJJInbgRAo02AJ9rE1KBZG1+JZU4ucYF2tJWsVN7fACeJphn
5Y8EHNeYqUvt3QyZrrwMbXM=
=667U
-----END PGP SIGNATURE-----