6.2 - RHSA-2013:0630

Problem Description:

Updated kernel packages that fix two security issues and several bugs 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - noarch, x86_64 Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, noarch, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, noarch, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. 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 the xen_iret() function in the Linux kernel used the DS (the CPU's Data Segment) register. A local, unprivileged user in a 32-bit, para-virtualized Xen hypervisor guest could use this flaw to crash the guest or, potentially, escalate their privileges. (CVE-2013-0228, Important)

* A flaw was found in the way file permission checks for the "/dev/cpu/[x]/msr" files were performed in restricted root environments (for example, when using a capability-based security model). A local user with the ability to write to these files could use this flaw to escalate their privileges to kernel level, for example, by writing to the SYSENTER_EIP_MSR register. (CVE-2013-0268, Important)

The CVE-2013-0228 issue was discovered by Andrew Jones of Red Hat.

This update also fixes several 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 these issues, and fix the bugs noted in the Technical Notes. The system must be rebooted for this update to take effect.

4. 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.

5. Bugs fixed (http://bugzilla.redhat.com/):

906309 - CVE-2013-0228 kernel: xen: userspace alterable %ds access in xen_iret() 908693 - CVE-2013-0268 kernel: x86/msr: /dev/cpu/*/msr local privilege escalation