(RHSA-2005:017) kernel security update

The Linux kernel handles the basic functions of the operating system.

This advisory includes fixes for the following 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.

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 flaw was discovered where an executable could cause a VMA overlap leading
to a crash. On Itanium systems, a local user could trigger this flaw by
creating a carefully crafted ELF binary. The Common Vulnerabilities and
Exposures project (cve.mitre.org) has assigned the name CAN-2005-0003 to
this issue.

iSEC Security Research and Georgi Guninski independently discovered a flaw
in the scm_send function in the auxiliary message layer. A local user
could create a carefully crafted auxiliary message which could cause a
denial of service (system hang). The Common Vulnerabilities and Exposures
project (cve.mitre.org) has assigned the name CAN-2004-1016 to this issue.

Kirill Korotaev found a flaw in load_elf_binary affecting kernels prior to
2.4.26. A local user could create a carefully crafted binary in such a
way that it would cause a denial of service (system crash). The Common
Vulnerabilities and Exposures project (cve.mitre.org) has assigned the
name CAN-2004-1234 to this issue.

These packages also fix issues in the io_edgeport driver (CAN-2004-1017), a
memory leak in ip_options_get (CAN-2004-1335), and missing VM_IO
flags in some drivers (CAN-2004-1057).

Olaf Kirch discovered that the recent security fixes for cmsg_len handling
(CAN-2004-1016) broke 32-bit compatibility on 64-bit platforms. 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.

All Red Hat Enterprise Linux 2.1 users running Itanium are advised to
upgrade their kernels to the packages listed in this erratum.