(RHSA-2011:0283) Moderate: kernel security, bug fix, and enhancement update

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

This update fixes the following security issues:

• A divide-by-zero flaw was found in the tcp_select_initial_window()
  function in the Linux kernel’s TCP/IP protocol suite implementation. A
  local, unprivileged user could use this flaw to trigger a denial of service
  by calling setsockopt() with certain options. (CVE-2010-4165, Moderate)

• A use-after-free flaw in the mprotect() system call in the Linux kernel
  could allow a local, unprivileged user to cause a local denial of service.
  (CVE-2010-4169, Moderate)

• A flaw was found in the Linux kernel execve() system call implementation.
  A local, unprivileged user could cause large amounts of memory to be
  allocated but not visible to the OOM (Out of Memory) killer, triggering a
  denial of service. (CVE-2010-4243, Moderate)

Red Hat would like to thank Steve Chen for reporting CVE-2010-4165, and
Brad Spengler for reporting CVE-2010-4243.

This update also fixes several bugs and adds two enhancements.
Documentation for these bug fixes and enhancements 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 and add the enhancements
noted in the Technical Notes. The system must be rebooted for this update
to take effect.