Important: kernel security and bug fix update

Updated kernel packages that fix several security issues and a bug 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.

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

These updated packages fix the following security issues:

* A security flaw was found in the Linux kernel memory copy routines, when
running on certain AMD64 systems. If an unsuccessful attempt to copy kernel
memory from source to destination memory locations occurred, the copy
routines did not zero the content at the destination memory location. This
could allow a local unprivileged user to view potentially sensitive data.
(CVE-2008-2729, Important)

* Alexey Dobriyan discovered a race condition in the Linux kernel
process-tracing system call, ptrace. A local unprivileged user could
use this flaw to cause a denial of service (kernel hang).
(CVE-2008-2365, Important)

* Tavis Ormandy discovered a deficiency in the Linux kernel 32-bit and
64-bit emulation. This could allow a local unprivileged user to prepare and
run a specially crafted binary, which would use this deficiency to leak
uninitialized and potentially sensitive data. (CVE-2008-0598, Important)

* 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 bug:

* On systems with a large number of CPUs (more than 16), multiple
applications calling the "times()" system call may have caused a system
hang.

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

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

433938 - CVE-2008-0598 kernel: linux x86_64 ia32 emulation leaks uninitialized data
437312 - CVE-2008-1367 Kernel doesn't clear DF for signal handlers
449101 - [4.7] System goes unresponsive if times() syscall is called concurrently on many cpus
449359 - CVE-2008-2365 kernel: ptrace: Crash on PTRACE_{ATTACH,DETACH} race
451271 - CVE-2008-2729 kernel: [x86_64] The string instruction version didn't zero the output on exception.

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-0598
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1367
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-2365
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-2729
http://www.redhat.com/security/updates/classification/#important