Updated kernel packages for Red Hat Enterprise Linux 2.1 that fix security vulnerabilities are now available.
The Linux kernel handles the basic functions of the operating system. A flaw was found in Linux kernel versions 2.4 and 2.6 for x86 and x86_64 that allowed local users to cause a denial of service (system crash) by triggering a signal handler with a certain sequence of fsave and frstor instructions. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0554 to this issue. Enhancements were committed to the 2.6 kernel by Al Viro which enabled the Sparse source code checking tool to check for a certain class of kernel bugs. A subset of these fixes also applies to various drivers in the 2.4 kernel. These flaws could lead to privilege escalation or access to kernel memory. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-0495 to these issues. All Red Hat Enterprise Linux 2.1 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum. These packages contain backported patches to correct these issues.