Red Hat 5.4 RHSA-2009:1243-02 Important Kernel Security Update

The kernel packages contain the Linux kernel, the core of any Linux operating system.
These updated packages fix the following security issues:
* it was discovered that, when executing a new process, the clear_child_tid pointer in the Linux kernel is not cleared. If this pointer points to a writable portion of the memory of the new program, the kernel could corrupt four bytes of memory, possibly leading to a local denial of service or privilege escalation. (CVE-2009-2848, Important)
* a flaw was found in the way the do_sigaltstack() function in the Linux kernel copies the stack_t structure to user-space. On 64-bit machines, this flaw could lead to a four-byte information leak. (CVE-2009-2847, Moderate)
* a flaw was found in the ext4 file system code. A local attacker could use this flaw to cause a denial of service by performing a resize operation on a specially-crafted ext4 file system. (CVE-2009-0745, Low)
* multiple flaws were found in the ext4 file system code. A local attacker could use these flaws to cause a denial of service by mounting a specially-crafted ext4 file system. (CVE-2009-0746, CVE-2009-0747, CVE-2009-0748, 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 5.4 Release Notes for information on the most significant of these changes:
https://docs.redhat.com/en/ Release_Notes/
Also, for details concerning every bug fixed in and every enhancement added to the kernel for this release, see the kernel chapter in the Red Hat Enterprise Linux 5.4 Technical Notes:
https://docs.redhat.com/en/ 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 5.4 Release Notes and Technical Notes. The system must be rebooted for this update to take effect.