kernel security update

CentOS Errata and Security Advisory CESA-2008:0211

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)

• 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)

• a flaw was found when performing asynchronous input or output operations
  on a FIFO special file. A local unprivileged user could use this flaw to
  cause a kernel panic. (CVE-2007-5001, Important)

• a flaw was found in the way core dump files were created. If a local user
  could get a root-owned process to dump a core file into a directory, which
  the user has write access to, they could gain read access to that core
  file. This could potentially grant unauthorized access to sensitive
  information. (CVE-2007-6206, Moderate)

• a buffer overflow was found in the Linux kernel ISDN subsystem. A local
  unprivileged user could use this flaw to cause a denial of service.
  (CVE-2007-6151, Moderate)

• a race condition found in the mincore system core could allow a local
  user to cause a denial of service (system hang). (CVE-2006-4814, Moderate)

• it was discovered that the Linux kernel handled string operations in the
  opposite way to the GNU Compiler Collection (GCC). This could allow a local
  unprivileged user to cause memory corruption. (CVE-2008-1367, Low)

As well, these updated packages fix the following bugs:

• a bug, which caused long delays when unmounting mounts containing a large
  number of unused dentries, has been resolved.

• in the previous kernel packages, the kernel was unable to handle certain
  floating point instructions on Itanium® architectures.

• on certain Intel CPUs, the Translation Lookaside Buffer (TLB) was not
  flushed correctly, which caused machine check errors.

Red Hat Enterprise Linux 3 users are advised to upgrade to these updated
packages, which contain backported patches to resolve these issues.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2008-May/077042.html
https://lists.centos.org/pipermail/centos-announce/2008-May/077043.html
https://lists.centos.org/pipermail/centos-announce/2008-May/077052.html
https://lists.centos.org/pipermail/centos-announce/2008-May/077056.html

Affected packages:
kernel
kernel-BOOT
kernel-doc
kernel-hugemem
kernel-hugemem-unsupported
kernel-smp
kernel-smp-unsupported
kernel-source
kernel-unsupported

Upstream details at:
https://access.redhat.com/errata/RHSA-2008:0211