CESA-2005:043: kernel security update

Description

Updated kernel packages that fix several security issues in CentOS Enterprise Linux 3 are now available.

The Linux kernel handles the basic functions of the operating system. This advisory includes fixes for several security issues: iSEC Security Research discovered a VMA handling flaw in the uselib(2) system call of the Linux kernel. A local user could make use of this flaw to gain elevated (root) privileges. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-1235 to this issue. A flaw was discovered where an executable could cause a VMA overlap leading to a crash. A local user could trigger this flaw by creating a carefully crafted a.out binary on 32-bit systems or a carefully crafted ELF binary on Itanium systems. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2005-0003 to this issue. iSEC Security Research discovered a flaw in the page fault handler code that could lead to local users gaining elevated (root) privileges on multiprocessor machines. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2005-0001 to this issue. A patch that coincidentally fixed this issue was committed to the Update 4 kernel release in December 2004. Therefore CentOS Linux 3 kernels provided by RHBA-2004:550 and subsequent updates are not vulnerable to this issue. A flaw in the system call filtering code in the audit subsystem included in CentOS Linux 3 allowed a local user to cause a crash when auditing was enabled. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2004-1237 to this issue. Olaf Kirch discovered that the recent security fixes for cmsg_len handling (CAN-2004-1016) broke 32-bit compatibility on 64-bit platforms such as AMD64 and Intel EM64T. A patch to correct this issue is included. A recent Internet Draft by Fernando Gont recommended that ICMP Source Quench messages be ignored by hosts. A patch to ignore these messages is included. Note: The kernel-unsupported package contains various drivers and modules that are unsupported and therefore might contain security problems that have not been addressed. All CentOS Linux 3 users are advised to upgrade their kernels to the packages associated with their machine architectures and configurations as listed in this erratum.