Synopsis

Moderate: kvm security and bug fix update

Type/Severity

Security Advisory: Moderate

Topic

Updated kvm packages that fix two security issues and one bug are now
available for Red Hat Enterprise Linux 5.

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. KVM is a Linux kernel module built for
the standard Red Hat Enterprise Linux kernel.

A flaw was found in the way the KVM_CREATE_IRQCHIP ioctl was handled.
Calling this ioctl when at least one virtual CPU (VCPU) already existed
could lead to a NULL pointer dereference later when the VCPU is scheduled
to run. A malicious user in the kvm group on the host could use this flaw
to crash the host. (CVE-2012-1601)

A flaw was found in the way device memory was handled during guest device
removal. Upon successful device removal, memory used by the device was not
properly unmapped from the corresponding IOMMU or properly released from
the kernel, leading to a memory leak. A malicious user in the kvm group on
the host who has the ability to assign a device to a guest could use this
flaw to crash the host. (CVE-2012-2121)

This update also fixes the following bug:

• An off-by-one error in the QEMU guest's memory management could, in rare
  cases, cause QEMU-KVM to crash due to a segmentation fault in
  tb_invalidate_phys_page_range() if a device initiated DMA into a specific
  guest address. In a reported case, this issue presented on a system that
  had a guest using the 8139cp network driver. (BZ#816207)
  

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 Workstation 5 x86_64

Fixes

• BZ - 808199 - CVE-2012-1601 kernel: kvm: irqchip_in_kernel() and vcpu->arch.apic inconsistency
• BZ - 814149 - CVE-2012-2121 kvm: device assignment page leak

CVEs

• CVE-2012-1601
• CVE-2012-2121

References

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

Red Hat Enterprise Linux Server 5

SRPM
kvm-83-249.el5_8.4.src.rpm	SHA-256: 2ff394f22f7e4de0b72e6bc98db0713cbea5af9104714f0bb0dcccecbccf9087
x86_64
kmod-kvm-83-249.el5_8.4.x86_64.rpm	SHA-256: e1ebe51a3a9a3a92961f37f59d7a9b8170916793b2cdd37dc3c6e7f52cf4106f
kmod-kvm-debug-83-249.el5_8.4.x86_64.rpm	SHA-256: c0d278c05bae1b6ebee3d70a005e5f081764e75532fec63853531fa06e428e6a
kvm-83-249.el5_8.4.x86_64.rpm	SHA-256: 25822db48d3ba6b3543fa9f670bbfb4eedab01c5580344465c59fd3947d7468c
kvm-debuginfo-83-249.el5_8.4.x86_64.rpm	SHA-256: 4610d7162e36f1f4819d3b0be47a259ff0182723eb1fa7e8a2dba9b09d9ebd43
kvm-qemu-img-83-249.el5_8.4.x86_64.rpm	SHA-256: 7097b89e6792951b6691f822b3ff5c206af7bff8c3f26bb0c4ddaf1243a78f97
kvm-tools-83-249.el5_8.4.x86_64.rpm	SHA-256: 6e870205e75c7a6fc3e631ac3265e5926d66647c4eb051f4c527c586b6181831

Red Hat Enterprise Linux Workstation 5

SRPM
kvm-83-249.el5_8.4.src.rpm	SHA-256: 2ff394f22f7e4de0b72e6bc98db0713cbea5af9104714f0bb0dcccecbccf9087
x86_64
kmod-kvm-83-249.el5_8.4.x86_64.rpm	SHA-256: e1ebe51a3a9a3a92961f37f59d7a9b8170916793b2cdd37dc3c6e7f52cf4106f
kmod-kvm-debug-83-249.el5_8.4.x86_64.rpm	SHA-256: c0d278c05bae1b6ebee3d70a005e5f081764e75532fec63853531fa06e428e6a
kvm-83-249.el5_8.4.x86_64.rpm	SHA-256: 25822db48d3ba6b3543fa9f670bbfb4eedab01c5580344465c59fd3947d7468c
kvm-debuginfo-83-249.el5_8.4.x86_64.rpm	SHA-256: 4610d7162e36f1f4819d3b0be47a259ff0182723eb1fa7e8a2dba9b09d9ebd43
kvm-qemu-img-83-249.el5_8.4.x86_64.rpm	SHA-256: 7097b89e6792951b6691f822b3ff5c206af7bff8c3f26bb0c4ddaf1243a78f97
kvm-tools-83-249.el5_8.4.x86_64.rpm	SHA-256: 6e870205e75c7a6fc3e631ac3265e5926d66647c4eb051f4c527c586b6181831