RHSA-2012:0690 - Security Advisory

Topic

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

The Red Hat Security Response Team has rated this update as having
important security impact. A Common Vulnerability Scoring System (CVSS)
base score, which gives a detailed severity rating, is available from the
CVE link 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 issue:

• It was found that the data_len parameter of the sock_alloc_send_pskb()

function in the Linux kernel's networking implementation was not validated
before use. A local user with access to a TUN/TAP virtual interface could
use this flaw to crash the system or, potentially, escalate their
privileges. Note that unprivileged users cannot access TUN/TAP devices
until the root user grants them access. (CVE-2012-2136, Important)

This update also fixes various bugs. 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 this issue, and fix the bugs noted in the Technical
Notes. 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 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 816289 - CVE-2012-2136 kernel: net: insufficient data_len validation in sock_alloc_send_pskb()

CVEs

• CVE-2012-2136

References

• https://access.redhat.com/security/updates/classification/#important
• https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/5.8_Technical_Notes/kernel.html#RHSA-2012-0690