(RHSA-2010:0178) Important: Red Hat Enterprise Linux 5.5 kernel security and bug fix update

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

This update fixes the following security issues:

• a race condition was found in the mac80211 implementation, a framework
  used for writing drivers for wireless devices. An attacker could trigger
  this flaw by sending a Delete Block ACK (DELBA) packet to a target system,
  resulting in a remote denial of service. Note: This issue only affected
  users on 802.11n networks, and that also use the iwlagn driver with Intel
  wireless hardware. (CVE-2009-4027, Important)

• a flaw was found in the gfs2_lock() implementation. The GFS2 locking code
  could skip the lock operation for files that have the S_ISGID bit
  (set-group-ID on execution) in their mode set. A local, unprivileged user
  on a system that has a GFS2 file system mounted could use this flaw to
  cause a kernel panic. (CVE-2010-0727, Moderate)

• a divide-by-zero flaw was found in the ext4 file system code. A local
  attacker could use this flaw to cause a denial of service by mounting a
  specially-crafted ext4 file system. (CVE-2009-4307, Low)

These updated packages also include several hundred bug fixes for and
enhancements to the Linux kernel. Space precludes documenting each of these
changes in this advisory and users are directed to the Red Hat Enterprise
Linux 5.5 Release Notes for information on the most significant of these
changes:

http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5.5/html/Release_Notes/

Also, for details concerning every bug fixed in and every enhancement added
to the kernel for this release, refer to the kernel chapter in the Red Hat
Enterprise Linux 5.5 Technical Notes:

http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5.5/html/Technical_Notes/kernel.html

All Red Hat Enterprise Linux 5 users are advised to install these updated
packages, which address these vulnerabilities as well as fixing the bugs
and adding the enhancements noted in the Red Hat Enterprise Linux 5.5
Release Notes and Technical Notes. The system must be rebooted for this
update to take effect.