glibc security update

Updated glibc packages that fix a number of bugs as well as a buffer
overflow issue are now available.

The GNU libc package (known as glibc) contains the standard C libraries
used by applications.

A bug in the getgrouplist function can cause a buffer overflow if
the size of the group list is too small to hold all the user's groups.
This overflow can cause segmentation faults in user applications, which may
have security implications, depending on the application in question. This
vulnerability exists only when an administrator has placed a user in a
number of groups larger than that expected by an application. Therefore,
there is no risk in instances where users are members of few groups. The
Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned
the name CAN-2003-0689 to this issue.

In addition, a number of other bugs in glibc have been fixed:

- An error prevented gdb from correctly debugging programs linked to
libpthread.

- A race condition existed in the malloc routine for IA64 platforms, which
could cause memory corruption.

- An error in pthread_spinlocks prevents spinlocks from functioning
correctly on IA64 platforms.

All users should upgrade to these errata packages, which contain patches to
the glibc libraries correcting these issues.

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

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade. Only those
RPMs which are currently installed will be updated. Those RPMs which are
not installed but included in the list will not be updated. Note that you
can also use wildcards (*.rpm) if your current directory *only* contains the
desired RPMs.

Please note that this update is also available via Red Hat Network. Many
people find this an easier way to apply updates. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

101691 - Buffer overrun in getgrouplist function in initgroups.c
101998 - Broken pthread_spinlocks
82640 - Gdb unable to debug threaded apps
90672 - RHEL 3 and RHELAS2.1 QU3 IPF errata: Corrupted linked list due to memory ordering issues

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2003-0689

barrier, debugging, linuxthreads_db, malloc, threads