RHSA-2013:0911 - Security Advisory

Topic

Updated kernel packages that fix three security issues, several bugs, and
add one enhancement are now available for Red Hat Enterprise Linux 6.

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

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

This update fixes the following security issues:

• A flaw was found in the way KVM (Kernel-based Virtual Machine)

initialized a guest's registered pv_eoi (paravirtualized end-of-interrupt)
indication flag when entering the guest. An unprivileged guest user could
potentially use this flaw to crash the host. (CVE-2013-1935, Important)

• A missing sanity check was found in the kvm_set_memory_region() function

in KVM, allowing a user-space process to register memory regions pointing
to the kernel address space. A local, unprivileged user could use this flaw
to escalate their privileges. (CVE-2013-1943, Important)

• A double free flaw was found in the Linux kernel's Virtual Ethernet

Tunnel driver (veth). A remote attacker could possibly use this flaw to
crash a target system. (CVE-2013-2017, Moderate)

Red Hat would like to thank IBM for reporting the CVE-2013-1935 issue and
Atzm WATANABE of Stratosphere Inc. for reporting the CVE-2013-2017 issue.
The CVE-2013-1943 issue was discovered by Michael S. Tsirkin of Red Hat.

This update also fixes several bugs and adds one enhancement. Documentation
for these changes will be available shortly from the Technical Notes
document linked to in the References section.

Users should upgrade to these updated packages, which contain backported
patches to correct these issues and add this enhancement. The system must
be rebooted 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/knowledge/articles/11258

To install kernel packages manually, use "rpm -ivh [package]". Do not
use "rpm -Uvh" as that will remove the running kernel binaries from
your system. You may use "rpm -e" to remove old kernels after
determining that the new kernel functions properly on your system.

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 6.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.4 i386
• Red Hat Enterprise Linux Server - AUS 6.4 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• 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 6.4 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.4 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Gluster Storage Server for On-premise 2.1 x86_64
• Red Hat Storage for Public Cloud (via RHUI) 2.1 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.4 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.4 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 949981 - CVE-2013-1935 kernel: kvm: pv_eoi guest updates with interrupts disabled
• BZ - 950490 - CVE-2013-1943 kernel: kvm: missing check in kvm_set_memory_region()
• BZ - 957705 - CVE-2013-2017 kernel: veth: double-free flaw in case of congestion

CVEs

• CVE-2013-1935
• CVE-2013-1943
• CVE-2013-2017
• CVE-2013-2188

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/6.4_Technical_Notes/kernel.html