RHSA-2014:0927 - Security Advisory

Topic

Updated qemu-kvm packages that fix multiple security issues and various
bugs are now available for Red Hat Enterprise Linux 7.

The Red Hat Security Response Team has rated this update as having Moderate
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.

Description

KVM (Kernel-based Virtual Machine) is a full virtualization solution for
Linux on AMD64 and Intel 64 systems. The qemu-kvm package provides the
user-space component for running virtual machines using KVM.

Two integer overflow flaws were found in the QEMU block driver for QCOW
version 1 disk images. A user able to alter the QEMU disk image files
loaded by a guest could use either of these flaws to corrupt QEMU process
memory on the host, which could potentially result in arbitrary code
execution on the host with the privileges of the QEMU process.
(CVE-2014-0222, CVE-2014-0223)

Multiple buffer overflow, input validation, and out-of-bounds write flaws
were found in the way virtio, virtio-net, virtio-scsi, usb, and hpet
drivers of QEMU handled state loading after migration. A user able to alter
the savevm data (either on the disk or over the wire during migration)
could use either of these flaws to corrupt QEMU process memory on the
(destination) host, which could potentially result in arbitrary code
execution on the host with the privileges of the QEMU process.
(CVE-2013-4148, CVE-2013-4149, CVE-2013-4150, CVE-2013-4151, CVE-2013-4527,
CVE-2013-4529, CVE-2013-4535, CVE-2013-4536, CVE-2013-4541, CVE-2013-4542,
CVE-2013-6399, CVE-2014-0182, CVE-2014-3461)

These issues were discovered by Michael S. Tsirkin, Anthony Liguori and
Michael Roth of Red Hat: CVE-2013-4148, CVE-2013-4149, CVE-2013-4150,
CVE-2013-4151, CVE-2013-4527, CVE-2013-4529, CVE-2013-4535, CVE-2013-4536,
CVE-2013-4541, CVE-2013-4542, CVE-2013-6399, CVE-2014-0182, and
CVE-2014-3461.

This update also fixes the following bugs:

• Previously, QEMU did not free pre-allocated zero clusters correctly and

the clusters under some circumstances leaked. With this update,
pre-allocated zero clusters are freed appropriately and the cluster leaks
no longer occur. (BZ#1110188)

• Prior to this update, the QEMU command interface did not properly handle

resizing of cache memory during guest migration, causing QEMU to terminate
unexpectedly with a segmentation fault and QEMU to fail. This update fixes
the related code and QEMU no longer crashes in the described situation.
(BZ#1110191)

• Previously, when a guest device was hot unplugged, QEMU correctly removed

the corresponding file descriptor watch but did not re-create it after the
device was re-connected. As a consequence, the guest became unable to
receive any data from the host over this device. With this update, the file
descriptor's watch is re-created and the guest in the above scenario can
communicate with the host as expected. (BZ#1110219)

• Previously, the QEMU migration code did not account for the gaps caused

by hot unplugged devices and thus expected more memory to be transferred
during migrations. As a consequence, guest migration failed to complete
after multiple devices were hot unplugged. In addition, the migration info
text displayed erroneous values for the "remaining ram" item. With this
update, QEMU calculates memory after a device has been unplugged correctly,
and any subsequent guest migrations proceed as expected. (BZ#1110189)

All qemu-kvm users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. After installing this
update, shut down all running virtual machines. Once all virtual machines
have shut down, start them again 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/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 - AUS 7.3 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 Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 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 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

Fixes

• BZ - 1066334 - CVE-2013-4148 qemu: virtio-net: buffer overflow on invalid state load
• BZ - 1066337 - CVE-2013-4149 qemu: virtio-net: out-of-bounds buffer write on load
• BZ - 1066340 - CVE-2013-4150 qemu: virtio-net: out-of-bounds buffer write on invalid state load
• BZ - 1066342 - CVE-2013-4151 qemu: virtio: out-of-bounds buffer write on invalid state load
• BZ - 1066347 - CVE-2013-4527 qemu: hpet: buffer overrun on invalid state load
• BZ - 1066353 - CVE-2013-4529 qemu: hw/pci/pcie_aer.c: buffer overrun on invalid state load
• BZ - 1066361 - CVE-2013-6399 qemu: virtio: buffer overrun on incoming migration
• BZ - 1066382 - CVE-2013-4542 qemu: virtio-scsi: buffer overrun on invalid state load
• BZ - 1066384 - CVE-2013-4541 qemu: usb: insufficient sanity checking of setup_index+setup_len in post_load
• BZ - 1066401 - CVE-2013-4535 CVE-2013-4536 qemu: virtio: insufficient validation of num_sg when mapping
• BZ - 1088986 - CVE-2014-0182 qemu: virtio: out-of-bounds buffer write on state load with invalid config_len
• BZ - 1096821 - CVE-2014-3461 Qemu: usb: fix up post load checks
• BZ - 1097216 - CVE-2014-0222 Qemu: qcow1: validate L2 table size to avoid integer overflows
• BZ - 1097222 - CVE-2014-0223 Qemu: qcow1: validate image size to avoid out-of-bounds memory access
• BZ - 1110188 - qcow2 corruptions (leaked clusters after installing a rhel7 guest using virtio_scsi)
• BZ - 1110189 - migration can not finish with 1024k 'remaining ram' left after hotunplug 4 nics
• BZ - 1110191 - Reduce the migrate cache size during migration causes qemu segment fault
• BZ - 1110219 - Guest can't receive any character transmitted from host after hot unplugging virtserialport then hot plugging again

CVEs

• CVE-2013-4148
• CVE-2013-4149
• CVE-2013-4150
• CVE-2013-4151
• CVE-2013-4527
• CVE-2013-4529
• CVE-2013-4535
• CVE-2013-4536
• CVE-2013-4541
• CVE-2013-4542
• CVE-2013-6399
• CVE-2014-0182
• CVE-2014-0222
• CVE-2014-0223
• CVE-2014-3461

References

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