Topic

Updated kernel packages that fix various security issues and several bugs
are now available for Red Hat Enterprise Linux 4.

This update has been rated as having important security impact by the Red
Hat Security Response Team.

Description

The kernel packages contain the Linux kernel, the core of any Linux
operating system.

These updated packages fix the following security issues:

• the absence of a protection mechanism when attempting to access a

critical section of code has been found in the Linux kernel open file
descriptors control mechanism, fcntl. This could allow a local unprivileged
user to simultaneously execute code, which would otherwise be protected
against parallel execution. As well, a race condition when handling locks
in the Linux kernel fcntl functionality, may have allowed a process
belonging to a local unprivileged user to gain re-ordered access to the
descriptor table. (CVE-2008-1669, Important)

• on AMD64 architectures, the possibility of a kernel crash was discovered

by testing the Linux kernel process-trace ability. This could allow a local
unprivileged user to cause a denial of service (kernel crash).
(CVE-2008-1615, Important)

• the absence of a protection mechanism when attempting to access a

critical section of code, as well as a race condition, have been found
in the Linux kernel file system event notifier, dnotify. This could allow a
local unprivileged user to get inconsistent data, or to send arbitrary
signals to arbitrary system processes. (CVE-2008-1375, Important)

Red Hat would like to thank Nick Piggin for responsibly disclosing the
following issue:

• when accessing kernel memory locations, certain Linux kernel drivers

registering a fault handler did not perform required range checks. A local
unprivileged user could use this flaw to gain read or write access to
arbitrary kernel memory, or possibly cause a kernel crash.
(CVE-2008-0007, Important)

• the possibility of a kernel crash was found in the Linux kernel IPsec

protocol implementation, due to improper handling of fragmented ESP
packets. When an attacker controlling an intermediate router fragmented
these packets into very small pieces, it would cause a kernel crash on the
receiving node during packet reassembly. (CVE-2007-6282, Important)

• a flaw in the MOXA serial driver could allow a local unprivileged user

to perform privileged operations, such as replacing firmware.
(CVE-2005-0504, Important)

As well, these updated packages fix the following bugs:

• multiple buffer overflows in the neofb driver have been resolved. It was

not possible for an unprivileged user to exploit these issues, and as such,
they have not been handled as security issues.

• a kernel panic, due to inconsistent detection of AGP aperture size, has

been resolved.

• a race condition in UNIX domain sockets may have caused "recv()" to

return zero. In clustered configurations, this may have caused unexpected
failovers.

• to prevent link storms, network link carrier events were delayed by up to

one second, causing unnecessary packet loss. Now, link carrier events are
scheduled immediately.

• a client-side race on blocking locks caused large time delays on NFS file

systems.

• in certain situations, the libATA sata_nv driver may have sent commands

with duplicate tags, which were rejected by SATA devices. This may have
caused infinite reboots.

• running the "service network restart" command may have caused networking

to fail.

• a bug in NFS caused cached information about directories to be stored

for too long, causing wrong attributes to be read.

• on systems with a large highmem/lowmem ratio, NFS write performance may

have been very slow when using small files.

• a bug, which caused network hangs when the system clock was wrapped

around zero, has been resolved.

Red Hat Enterprise Linux 4 users are advised to upgrade to these updated
packages, which contain backported patches to resolve these issues.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188

Affected Products

• Red Hat Enterprise Linux Server 4 x86_64
• Red Hat Enterprise Linux Server 4 ia64
• Red Hat Enterprise Linux Server 4 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.6 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.6 i386
• Red Hat Enterprise Linux Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 i386
• Red Hat Enterprise Linux for IBM z Systems 4 s390x
• Red Hat Enterprise Linux for IBM z Systems 4 s390
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 4.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 4.6 s390
• Red Hat Enterprise Linux for Power, big endian 4 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 4.6 ppc

Fixes

• BZ - 404291 - CVE-2007-6282 IPSec ESP kernel panics
• BZ - 423111 - CVE-2005-0504 Buffer overflow in moxa driver
• BZ - 428961 - CVE-2008-0007 kernel: insufficient range checks in fault handlers with mremap
• BZ - 431430 - CVE-2008-1615 kernel: ptrace: Unprivileged crash on x86_64 %cs corruption
• BZ - 435122 - [RHEL4.6] In unix domain sockets, recv() may incorrectly return zero
• BZ - 436102 - Fake ARP dropped after migration leading to loss of network connectivity
• BZ - 436129 - LTC41942-30 second flock() calls against files stored on a NetApp while using NFS
• BZ - 436499 - libata: sata_nv may send commands with duplicate tags
• BZ - 436749 - HP-Japan Network stack hang after service network restart
• BZ - 437788 - NFS: Fix directory caching problem - with test case and patch.
• BZ - 438345 - [2.6.9-55.9] VM pagecache reclaim patch causes high latency on systems with large highmem/lowmem ratios
• BZ - 438477 - Since "Patch2037: linux-2.6.9-vm-balance.patch" my NFS performance is poorly
• BZ - 439754 - CVE-2008-1375 kernel: race condition in dnotify (local DoS, local roothole possible)
• BZ - 443433 - CVE-2008-1669 kernel: add rcu_read_lock() to fcheck() in both dnotify, locks.c and fix fcntl store/load race in locks.c

CVEs

• CVE-2005-0504
• CVE-2008-1669
• CVE-2008-0007
• CVE-2008-1375
• CVE-2007-6282
• CVE-2008-1615

References

• http://www.redhat.com/security/updates/classification/#important