(RHSA-2005:043) kernel security update

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 Red Hat Enterprise 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 Red Hat Enterprise 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 Red Hat Enterprise Linux 3 users are advised to upgrade their
kernels to the packages associated with their machine architectures
and configurations as listed in this erratum.