sa_restorer information leak
CVE: CVE-2013-0914
Component: Kernel
Severity: Low
Release date: 2013-03-11T00:00:00+00:00

The flush_signal_handlers function in kernel/signal.c in the Linux kernel before 3.8.4 preserves the value of the sa_restorer field across an exec operation, which makes it easier for local users to bypass the ASLR protection mechanism via a crafted application containing a sigaction system call.

Statement: This issue affects the version of Linux kernel as shipped with Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG 2. Future kernel updates for Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG 2 may address this issue.

Remediation:
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.
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/site/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.
Before applying this update, make sure all previously released errata
relevant to your system have been applied.

Details on how to use the Red Hat Network to apply this update are
available at https://access.redhat.com/site/articles/11258

This Red Hat OpenStack 3.0 kernel may be installed by running this command
while logged in as the root user on a system that has the required
entitlements and subscriptions attached:

# yum install "kernel-2.6.*.openstack.el6.x86_64"

Documentation for both stable and preview releases of Red Hat OpenStack is
available at:

https://access.redhat.com/site/documentation/en-US/Red_Hat_OpenStack/

In particular it is highly recommended that all users read the Release
Notes document for the relevant Red Hat OpenStack release prior to
installation.
This update also fixes multiple 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 upgrade the kernel-rt
kernel to version kernel-rt-3.6.11.2-rt33, correct these issues, and fix
the bugs noted in the Red Hat Enterprise MRG 2 Technical Notes. The system
must be rebooted for this update to take effect.

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.