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. * 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. * 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 killer, triggering a denial of service. 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.