Issued:
2012-01-23
Updated:
2012-01-23

RHSA-2012:0052 - Important: kernel security and bug fix update

Synopsis

Important: kernel security and bug fix update

Type/Severity

Security Advisory Important

Topic

Updated kernel packages that fix one security issue and three bugs are now available for 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.

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 permissions were not checked properly in the Linux kernel when handling the /proc/[pid]/mem writing functionality. A local, unprivileged user could use this flaw to escalate their privileges. Refer to Red Hat Knowledgebase article DOC-69129, linked to in the References, for further information. (CVE-2012-0056, Important)

Red Hat would like to thank Jüri Aedla for reporting this issue.

This update fixes the following bugs:

  • The RHSA-2011:1849 kernel update introduced a bug in the Linux kernel scheduler, causing a "WARNING: at kernel/sched.c:5915 thread_return" message and a call trace to be logged. This message was harmless, and was not due to any system malfunctions or adverse behavior. With this update, the WARN_ON_ONCE() call in the scheduler that caused this harmless message has been removed. (BZ#768288)

  • The RHSA-2011:1530 kernel update introduced a regression in the way the Linux kernel maps ELF headers for kernel modules into kernel memory. If a third-party kernel module is compiled on a Red Hat Enterprise Linux system with a kernel prior to RHSA-2011:1530, then loading that module on a system with RHSA-2011:1530 kernel would result in corruption of one byte in the memory reserved for the module. In some cases, this could prevent the module from functioning correctly. (BZ#769595)

  • On some SMP systems the tsc may erroneously be marked as unstable during early system boot or while the system is under heavy load. A "Clocksource tsc unstable" message was logged when this occurred. As a result the system would switch to the slower access, but higher precision HPET clock.

The "tsc=reliable" kernel parameter is supposed to avoid this problem by indicating that the system has a known good clock, however, the parameter only affected run time checks. A fix has been put in to avoid the boot time checks so that the TSC remains as the clock for the duration of system runtime. (BZ#755867)

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 This content is not included.https://access.redhat.com/kb/docs/DOC-11259

Affected Products

ProductVersionArch
Red Hat Storage2.0x86_64
Red Hat Storage for Public Cloud (via RHUI)2.0x86_64
Red Hat Gluster Storage Server for On-premise2.0x86_64
Red Hat Enterprise Linux for x86_64 - Extended Update Support6.2x86_64
Red Hat Enterprise Linux for x86_64 - Extended Update Support6.2i386
Red Hat Enterprise Linux for Scientific Computing6x86_64
Red Hat Enterprise Linux for Power, big endian6ppc64
Red Hat Enterprise Linux for Power, big endian - Extended Update Support6.2ppc64
Red Hat Enterprise Linux for IBM z Systems6s390x
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support6.2s390x
Red Hat Enterprise Linux Workstation6x86_64
Red Hat Enterprise Linux Workstation6i386
Red Hat Enterprise Linux Server6x86_64
Red Hat Enterprise Linux Server6i386
Red Hat Enterprise Linux Server from RHUI6x86_64
Red Hat Enterprise Linux Server from RHUI6i386
Red Hat Enterprise Linux Server - Retired Extended Life Cycle Support6x86_64
Red Hat Enterprise Linux Server - Extended Update Support from RHUI6.2x86_64
Red Hat Enterprise Linux Server - Extended Update Support from RHUI6.2i386
Red Hat Enterprise Linux Server - Extended Life Cycle Support6x86_64
Red Hat Enterprise Linux Server - Extended Life Cycle Support6i386
Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension6x86_64
Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension6i386
Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems)6s390x
Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems)6s390x
Red Hat Enterprise Linux Server - AUS6.2x86_64
Red Hat Enterprise Linux Desktop6x86_64
Red Hat Enterprise Linux Desktop6i386

Updated Packages

  • kernel-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-doc-2.6.32-220.4.1.el6.noarch.rpm
  • kernel-devel-2.6.32-220.4.1.el6.x86_64.rpm
  • kernel-debug-debuginfo-2.6.32-220.4.1.el6.x86_64.rpm
  • perf-2.6.32-220.4.1.el6.i686.rpm
  • kernel-debug-debuginfo-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-headers-2.6.32-220.4.1.el6.x86_64.rpm
  • kernel-debug-2.6.32-220.4.1.el6.ppc64.rpm
  • perf-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-headers-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-headers-2.6.32-220.4.1.el6.i686.rpm
  • kernel-debug-devel-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-kdump-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-debug-debuginfo-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-debug-devel-2.6.32-220.4.1.el6.x86_64.rpm
  • perf-debuginfo-2.6.32-220.4.1.el6.s390x.rpm
  • python-perf-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-debuginfo-2.6.32-220.4.1.el6.x86_64.rpm
  • kernel-debug-devel-2.6.32-220.4.1.el6.i686.rpm
  • kernel-debug-2.6.32-220.4.1.el6.x86_64.rpm
  • kernel-debuginfo-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-debuginfo-common-ppc64-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-devel-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-2.6.32-220.4.1.el6.s390x.rpm
  • python-perf-2.6.32-220.4.1.el6.x86_64.rpm
  • kernel-kdump-debuginfo-2.6.32-220.4.1.el6.s390x.rpm
  • perf-debuginfo-2.6.32-220.4.1.el6.i686.rpm
  • kernel-debug-2.6.32-220.4.1.el6.s390x.rpm
  • python-perf-2.6.32-220.4.1.el6.i686.rpm
  • kernel-debuginfo-common-x86_64-2.6.32-220.4.1.el6.x86_64.rpm
  • perf-2.6.32-220.4.1.el6.x86_64.rpm
  • kernel-firmware-2.6.32-220.4.1.el6.noarch.rpm
  • kernel-kdump-devel-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-debuginfo-common-s390x-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-debuginfo-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-devel-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-debuginfo-2.6.32-220.4.1.el6.i686.rpm
  • kernel-debug-devel-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-headers-2.6.32-220.4.1.el6.s390x.rpm
  • kernel-devel-2.6.32-220.4.1.el6.i686.rpm
  • kernel-debug-debuginfo-2.6.32-220.4.1.el6.i686.rpm
  • kernel-debuginfo-common-i686-2.6.32-220.4.1.el6.i686.rpm
  • python-perf-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-bootwrapper-2.6.32-220.4.1.el6.ppc64.rpm
  • perf-debuginfo-2.6.32-220.4.1.el6.ppc64.rpm
  • kernel-debug-2.6.32-220.4.1.el6.i686.rpm
  • kernel-2.6.32-220.4.1.el6.i686.rpm
  • kernel-2.6.32-220.4.1.el6.src.rpm
  • perf-debuginfo-2.6.32-220.4.1.el6.x86_64.rpm
  • kernel-2.6.32-220.4.1.el6.x86_64.rpm
  • perf-2.6.32-220.4.1.el6.s390x.rpm

Fixes

CVEs

References

Additional information