Synopsis

Important: kvm security update

Type/Severity

Security Advisory: Important

Topic

Updated kvm packages that fix three security issues are now available for
Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having
important 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. KVM is a Linux kernel module built for
the standard Red Hat Enterprise Linux kernel.

A flaw was found in the way KVM handled guest time updates when the buffer
the guest registered by writing to the MSR_KVM_SYSTEM_TIME machine state
register (MSR) crossed a page boundary. A privileged guest user could use
this flaw to crash the host or, potentially, escalate their privileges,
allowing them to execute arbitrary code at the host kernel level.
(CVE-2013-1796)

A potential use-after-free flaw was found in the way KVM handled guest time
updates when the GPA (guest physical address) the guest registered by
writing to the MSR_KVM_SYSTEM_TIME machine state register (MSR) fell into a
movable or removable memory region of the hosting user-space process (by
default, QEMU-KVM) on the host. If that memory region is deregistered from
KVM using KVM_SET_USER_MEMORY_REGION and the allocated virtual memory
reused, a privileged guest user could potentially use this flaw to
escalate their privileges on the host. (CVE-2013-1797)

A flaw was found in the way KVM emulated IOAPIC (I/O Advanced Programmable
Interrupt Controller). A missing validation check in the
ioapic_read_indirect() function could allow a privileged guest user to
crash the host, or read a substantial portion of host kernel memory.
(CVE-2013-1798)

Red Hat would like to thank Andrew Honig of Google for reporting all of
these issues.

All users of kvm are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. Note that the procedure
in the Solution section must be performed before this update will 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/knowledge/articles/11258

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.

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support 5.9 x86_64
• Red Hat Enterprise Linux Server - AUS 5.9 x86_64
• Red Hat Enterprise Linux Workstation 5 x86_64

Fixes

• BZ - 917012 - CVE-2013-1796 kernel: kvm: buffer overflow in handling of MSR_KVM_SYSTEM_TIME
• BZ - 917013 - CVE-2013-1797 kernel: kvm: after free issue with the handling of MSR_KVM_SYSTEM_TIME
• BZ - 917017 - CVE-2013-1798 kernel: kvm: out-of-bounds access in ioapic indirect register reads

CVEs

• CVE-2013-1798
• CVE-2013-1796
• CVE-2013-1797

References

• https://access.redhat.com/security/updates/classification/#important

Red Hat Enterprise Linux Server 5

SRPM
kvm-83-262.el5_9.3.src.rpm	SHA-256: fc044dd0631994be73fc66739085a62511e2fd564f60a653965a2564114517e0
x86_64
kmod-kvm-83-262.el5_9.3.x86_64.rpm	SHA-256: b178f4729bc93c6207a88ee3621f40e9578c0cab83feef0c929d7968214a1608
kmod-kvm-debug-83-262.el5_9.3.x86_64.rpm	SHA-256: fc5f6b0586bc0db7cf30968661664c1c8b04ffcc038068b4795d08083768bcb0
kvm-83-262.el5_9.3.x86_64.rpm	SHA-256: 5eaaccd514ec2d02a5b9b4d5aa12500a7879b0786e14d6eb955ad4393a9073ae
kvm-debuginfo-83-262.el5_9.3.x86_64.rpm	SHA-256: ac3a32813be958fe57c1d43d69d53f411e2f838f212610e4ec55ec4e2531ff0d
kvm-qemu-img-83-262.el5_9.3.x86_64.rpm	SHA-256: 533b4903f61acb86709306608db81fe7d009ba0e406f00dda7e6163109409998
kvm-tools-83-262.el5_9.3.x86_64.rpm	SHA-256: dbd7ef37e65b542c3abb6db6b7232375e9d3ce3a3432fddfb4e2bd445e1b16a6

Red Hat Enterprise Linux Server - Extended Update Support 5.9

SRPM
kvm-83-262.el5_9.3.src.rpm	SHA-256: fc044dd0631994be73fc66739085a62511e2fd564f60a653965a2564114517e0
x86_64
kmod-kvm-83-262.el5_9.3.x86_64.rpm	SHA-256: b178f4729bc93c6207a88ee3621f40e9578c0cab83feef0c929d7968214a1608
kmod-kvm-debug-83-262.el5_9.3.x86_64.rpm	SHA-256: fc5f6b0586bc0db7cf30968661664c1c8b04ffcc038068b4795d08083768bcb0
kvm-83-262.el5_9.3.x86_64.rpm	SHA-256: 5eaaccd514ec2d02a5b9b4d5aa12500a7879b0786e14d6eb955ad4393a9073ae
kvm-debuginfo-83-262.el5_9.3.x86_64.rpm	SHA-256: ac3a32813be958fe57c1d43d69d53f411e2f838f212610e4ec55ec4e2531ff0d
kvm-qemu-img-83-262.el5_9.3.x86_64.rpm	SHA-256: 533b4903f61acb86709306608db81fe7d009ba0e406f00dda7e6163109409998
kvm-tools-83-262.el5_9.3.x86_64.rpm	SHA-256: dbd7ef37e65b542c3abb6db6b7232375e9d3ce3a3432fddfb4e2bd445e1b16a6

Red Hat Enterprise Linux Server - AUS 5.9

SRPM
kvm-83-262.el5_9.3.src.rpm	SHA-256: fc044dd0631994be73fc66739085a62511e2fd564f60a653965a2564114517e0
x86_64
kmod-kvm-83-262.el5_9.3.x86_64.rpm	SHA-256: b178f4729bc93c6207a88ee3621f40e9578c0cab83feef0c929d7968214a1608
kmod-kvm-debug-83-262.el5_9.3.x86_64.rpm	SHA-256: fc5f6b0586bc0db7cf30968661664c1c8b04ffcc038068b4795d08083768bcb0
kvm-83-262.el5_9.3.x86_64.rpm	SHA-256: 5eaaccd514ec2d02a5b9b4d5aa12500a7879b0786e14d6eb955ad4393a9073ae
kvm-debuginfo-83-262.el5_9.3.x86_64.rpm	SHA-256: ac3a32813be958fe57c1d43d69d53f411e2f838f212610e4ec55ec4e2531ff0d
kvm-qemu-img-83-262.el5_9.3.x86_64.rpm	SHA-256: 533b4903f61acb86709306608db81fe7d009ba0e406f00dda7e6163109409998
kvm-tools-83-262.el5_9.3.x86_64.rpm	SHA-256: dbd7ef37e65b542c3abb6db6b7232375e9d3ce3a3432fddfb4e2bd445e1b16a6

Red Hat Enterprise Linux Workstation 5

SRPM
kvm-83-262.el5_9.3.src.rpm	SHA-256: fc044dd0631994be73fc66739085a62511e2fd564f60a653965a2564114517e0
x86_64
kmod-kvm-83-262.el5_9.3.x86_64.rpm	SHA-256: b178f4729bc93c6207a88ee3621f40e9578c0cab83feef0c929d7968214a1608
kmod-kvm-debug-83-262.el5_9.3.x86_64.rpm	SHA-256: fc5f6b0586bc0db7cf30968661664c1c8b04ffcc038068b4795d08083768bcb0
kvm-83-262.el5_9.3.x86_64.rpm	SHA-256: 5eaaccd514ec2d02a5b9b4d5aa12500a7879b0786e14d6eb955ad4393a9073ae
kvm-debuginfo-83-262.el5_9.3.x86_64.rpm	SHA-256: ac3a32813be958fe57c1d43d69d53f411e2f838f212610e4ec55ec4e2531ff0d
kvm-qemu-img-83-262.el5_9.3.x86_64.rpm	SHA-256: 533b4903f61acb86709306608db81fe7d009ba0e406f00dda7e6163109409998
kvm-tools-83-262.el5_9.3.x86_64.rpm	SHA-256: dbd7ef37e65b542c3abb6db6b7232375e9d3ce3a3432fddfb4e2bd445e1b16a6