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 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.

Description

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

This update fixes the following security issues:

• A NULL pointer dereference flaw was found in the nf_ct_frag6_reasm()
  function in the Linux kernel's netfilter IPv6 connection tracking
  implementation. A remote attacker could use this flaw to send
  specially-crafted packets to a target system that is using IPv6 and also
  has the nf_conntrack_ipv6 kernel module loaded, causing it to crash.
  (CVE-2012-2744, Important)
  
• A flaw was found in the way the Linux kernel's key management facility
  handled replacement session keyrings on process forks. A local,
  unprivileged user could use this flaw to cause a denial of service.
  (CVE-2012-2745, Moderate)
  

Red Hat would like to thank an anonymous contributor working with the
Beyond Security SecuriTeam Secure Disclosure program for reporting
CVE-2012-2744.

This update also fixes the following bugs:

• Previously introduced firmware files required for new Realtek chipsets
  contained an invalid prefix ("rtl_nic_") in the file names, for example
  "/lib/firmware/rtl_nic/rtl_nic_rtl8168d-1.fw". This update corrects these
  file names. For example, the aforementioned file is now correctly named
  "/lib/firmware/rtl_nic/rtl8168d-1.fw". (BZ#832359)
  
• This update blacklists the ADMA428M revision of the 2GB ATA Flash Disk
  device. This is due to data corruption occurring on the said device when
  the Ultra-DMA 66 transfer mode is used. When the
  "libata.force=5:pio0,6:pio0" kernel parameter is set, the aforementioned
  device works as expected. (BZ#832363)
  
• On Red Hat Enterprise Linux 6, mounting an NFS export from a Windows 2012
  server failed due to the fact that the Windows server contains support for
  the minor version 1 (v4.1) of the NFS version 4 protocol only, along with
  support for versions 2 and 3. The lack of the minor version 0 (v4.0)
  support caused Red Hat Enterprise Linux 6 clients to fail instead of
  rolling back to version 3 as expected. This update fixes this bug and
  mounting an NFS export works as expected. (BZ#832365)
  
• On ext4 file systems, when fallocate() failed to allocate blocks due to
  the ENOSPC condition (no space left on device) for a file larger than 4 GB,
  the size of the file became corrupted and, consequently, caused file system
  corruption. This was due to a missing cast operator in the
  "ext4_fallocate()" function. With this update, the underlying source code
  has been modified to address this issue, and file system corruption no
  longer occurs. (BZ#833034)
  

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
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.

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Update Support 6.3 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support 6.3 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.3 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.3 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.3 i386

Fixes

• BZ - 832365 - NFS mounts fail against Windows 8 servers [rhel-6.3.z]
• BZ - 833402 - CVE-2012-2744 kernel: netfilter: null pointer dereference in nf_ct_frag6_reasm()
• BZ - 833428 - CVE-2012-2745 kernel: cred: copy_process() should clear child->replacement_session_keyring

CVEs

• CVE-2012-2745
• CVE-2012-2744

References

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