RHSA-2010:0711 - Security Advisory

Topic

Updated kernel packages that fix one security issue are now available for
Red Hat Enterprise Linux 5.3 Extended Update Support.

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:

• The compat_alloc_user_space() function in the Linux kernel 32/64-bit

compatibility layer implementation was missing sanity checks. This function
could be abused in other areas of the Linux kernel if its length argument
can be controlled from user-space. On 64-bit systems, a local, unprivileged
user could use this flaw to escalate their privileges. (CVE-2010-3081,
Important)

Red Hat would like to thank Ben Hawkes for reporting this issue.

Red Hat is aware that a public exploit for this issue is available. Refer
to Knowledgebase article DOC-40265 for further details:
https://access.redhat.com/kb/docs/DOC-40265

Users should upgrade to these updated packages, which contain a backported
patch to correct this issue. 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
http://kbase.redhat.com/faq/docs/DOC-11259

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 5.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.3 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.3 i386
• Red Hat Enterprise Linux Server - AUS 5.3 x86_64
• Red Hat Enterprise Linux Server - AUS 5.3 ia64
• Red Hat Enterprise Linux Server - AUS 5.3 i386
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.3 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.3 ppc

Fixes

• BZ - 634457 - CVE-2010-3081 kernel: 64-bit Compatibility Mode Stack Pointer Underflow

CVEs

• CVE-2010-3081

References

• http://www.redhat.com/security/updates/classification/#important
• https://access.redhat.com/kb/docs/DOC-40265