RHBA-2013:0042 - Bug Fix Advisory

Topic

Updated ksh packages that fix several bugs and add various enhancements are now
available for Red Hat Enterprise Linux 5.

Description

KSH-93 is the most recent version of the KornShell by David Korn of AT&T Bell
Laboratories. KornShell is a shell programming language which is also compatible
with sh, the original Bourne Shell.

This update fixes the following bugs:

• Prior to this update, using the -R or -Z options of the typeset command did

not work as expected. When a variable was assigned to a field that was of
smaller size than the size of the variable, it would trim the incorrect values
from the variable. Consequently, the resulting value in the trimmed variable was
incorrect. The underlying source code has been modified and the typeset -R/-Z
command works as expected. (BZ#771188)

• Previously, ksh did not expand the tilde (~) character properly. For example,

characters in the tilde prefix were not treated as a login name but as a part of
the path and the "No such file or directory" message was displayed. The
underlying source code has been modified and tilde expansion now works as
expected in such a scenario. (BZ#802565)

• In certain cases, ksh unnecessarily called the vfork() function. An extra

process was created and it could be difficult to determine how many instances of
a script were running. A patch has been applied to address this problem, and
extra processes are no longer created if not required. (BZ#804925)

• Due to a missing patch that introduced the tsetio flag, the redirect output

behavior changed depending on what ksh version was used. With this update, the
missing patch was added and redirect output behavior is now consistent across
all versions of ksh. (BZ#811318)

• Previously, ksh did not close certain file descriptors prior to execution.

This could lead to a file descriptor leak, and certain applications could
consequently report error messages. With this update, file descriptors are
marked to be closed on execution if appropriate, so file descriptor leaks no
longer occur. (BZ#812930)

• Due to a bug in the typeset command, when executed with the -Z option, output

was being formatted to an incorrect width. As a result, exporting a
right-aligned variable of smaller size than the predefined field size caused it
to not be prepended with 0 characters. With this update, the typeset command
works as expected in the aforementioned scenario. (BZ#827522)

• Previously, ksh did not allocate the correct amount of memory for its data

structures containing information about file descriptors. When running a task
that used file descriptors extensively, ksh terminated unexpectedly with a
segmentation fault. With this update, the proper amount of memory is allocated,
and ksh no longer crashes if file descriptors are used extensively. (BZ#827613)

All users of the ksh are advised to upgrade to these updated packages, which fix
these bugs.

Solution

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

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 802565 - Tilda expansion failing in ksh

CVEs

(none)

References

(none)