RHSA-2012:0517 - Security Advisory

Topic

Updated kernel packages that fix one security issue and one bug are now
available for Red Hat Enterprise Linux 5.6 Extended Update Support.

The Red Hat Security Response Team has rated this update as having moderate
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:

• A flaw was found in the Linux kernel in the way splitting two extents in

ext4_ext_convert_to_initialized() worked. A local, unprivileged user with
the ability to mount and unmount ext4 file systems could use this flaw to
cause a denial of service. (CVE-2011-3638, Moderate)

Red Hat would like to thank Zheng Liu for reporting this issue.

This update also fixes the following bug:

• Starting with Red Hat Enterprise Linux 5.6, all devices that used the

ixgbe driver would stop stripping VLAN tags when the device entered
promiscuous mode. Placing a device in a bridge group causes the device to
enter promiscuous mode. This caused various issues under certain
configurations of bridging and VLANs. A patch has been provided to address
this issue and the devices now properly strip VLAN tags in the driver
whether in promiscuous mode or not. (BZ#809790)

Users should upgrade to these updated packages, which contain backported
patches to correct these issues. 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 for x86_64 - Extended Update Support 5.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 i386
• Red Hat Enterprise Linux Server - AUS 5.6 x86_64
• Red Hat Enterprise Linux Server - AUS 5.6 ia64
• Red Hat Enterprise Linux Server - AUS 5.6 i386
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.6 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.6 ppc
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.6 i386

Fixes

• BZ - 747942 - CVE-2011-3638 kernel: ext4: ext4_ext_insert_extent() kernel oops

CVEs

• CVE-2011-3638

References

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