Moderate: kernel security and bug fix update

Synopsis

Moderate: kernel security and bug fix update

Type/Severity

Security Advisory: Moderate

Topic

Updated kernel packages that fix multiple security issues and several bugs
are now available for Red Hat Enterprise Linux 5.

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

• A use-after-free flaw was found in the madvise() system call
  implementation in the Linux kernel. A local, unprivileged user could use
  this flaw to cause a denial of service or, potentially, escalate their
  privileges. (CVE-2012-3511, Moderate)
  
• A flaw was found in the way the Linux kernel's TCP/IP protocol suite
  implementation handled IPv6 sockets that used the UDP_CORK option. A local,
  unprivileged user could use this flaw to cause a denial of service.
  (CVE-2013-4162, Moderate)
  
• An information leak flaw in the Linux kernel could allow a local,
  unprivileged user to leak kernel memory to user-space. (CVE-2013-2141, Low)
  

Red Hat would like to thank Hannes Frederic Sowa for reporting
CVE-2013-4162.

This update also fixes the following bugs:

• A bug in the be2net driver prevented communication between NICs using
  be2net. This update applies a patch addressing this problem along with
  several other upstream patches that fix various other problems. Traffic
  between NICs using the be2net driver now proceeds as expected. (BZ#983864)
  
• A recent patch fixing a problem that prevented communication between
  NICs using the be2net driver caused the firmware of NICs to become
  unresponsive, and thus triggered a kernel panic. The problem was caused by
  unnecessary usage of a hardware workaround that allows skipping VLAN tag
  insertion. A patch has been applied and the workaround is now used only
  when the multi-channel configuration is enabled on the NIC. Note that the
  bug only affected the NICs with firmware version 4.2.xxxx. (BZ#999819)
  
• A bug in the autofs4 mount expiration code could cause the autofs4
  module to falsely report a busy tree of NFS mounts as "not in use".
  Consequently, automount attempted to unmount the tree and failed with
  a "failed to umount offset" error, leaving the mount tree to appear as
  empty directories. A patch has been applied to remove an incorrectly used
  autofs dentry mount check and the aforementioned problem no longer occurs.
  (BZ#1001488)
  
• A race condition in the be_open function in the be2net driver could
  trigger the BUG_ON() macro, which resulted in a kernel panic. A patch
  addressing this problem has been applied and the race condition is now
  avoided by enabling polling before enabling interrupts globally. The
  kernel no longer panics in this situation. (BZ#1005239)
  

All kernel users are advised to 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/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.

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Server - Extended Update Support 5.9 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support 5.9 ia64
• Red Hat Enterprise Linux Server - Extended Update Support 5.9 i386
• Red Hat Enterprise Linux Server - AUS 5.9 ia64
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.9 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.9 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.9 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.9 i386
• Red Hat Enterprise Linux Server - AUS 5.9 x86_64
• Red Hat Enterprise Linux Server - AUS 5.9 i386

Fixes

• BZ - 849734 - CVE-2012-3511 kernel: mm: use-after-free in madvise_remove()
• BZ - 970873 - CVE-2013-2141 Kernel: signal: information leak in tkill/tgkill
• BZ - 987627 - CVE-2013-4162 Kernel: net: panic while pushing pending data out of a IPv6 socket with UDP_CORK enabled

CVEs

• CVE-2012-3511
• CVE-2013-2141
• CVE-2013-4162

References

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