RHBA-2011:0304 - Bug Fix Advisory

Topic

An updated ksh package that fixes multiple bugs is 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:

• Due to a memory leak in the ksh executable, the performance of long running

scripts could decrease significantly over the time. With this update, the
underlying source code has been modified to prevent this memory leak, and the
execution of long running scripts is no longer slowed down. (BZ#674552)

• When a ksh script contained the "trap" command to capture a "SIGPIPE" signal,

sending this signal by using the built-in "echo" command could cause its output
to be incorrectly added to the redirected output of an external command. This
error has been fixed, and ksh now flushes the output buffer before redirecting
output streams. (BZ#675128)

• Due to incorrect signal handling, receiving a signal while still processing

the same one caused ksh to terminate unexpectedly with a segmentation fault.
With this update, the subsequent signals are deferred until the current one is
processed, and ksh no longer crashes. (BZ#675130)

• Previously, assigning a value to an array variable during the execution of the

"typeset" command could cause the shell to terminate unexpectedly with a
segmentation fault. This update corrects the array handling in this command, and
ksh no longer crashes. (BZ#675135)

All users of ksh are advised to upgrade to this updated package, which resolves
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
https://access.redhat.com/kb/docs/DOC-11259

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 for x86_64 - Extended Update Support 5.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.6 i386
• Red Hat Enterprise Linux Server - AUS 5.6 x86_64
• 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 IBM z Systems - Extended Update Support 5.6 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.6 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386
• Red Hat Enterprise Linux Server - AUS 5.6 ia64
• Red Hat Enterprise Linux Server - AUS 5.6 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 5.6 i386

Fixes

• BZ - 674552 - ksh memory leak significantly slows the execution of shell scripts
• BZ - 675128 - wrong redirections with SIGPIPE traps
• BZ - 675135 - ksh crashes

CVEs

(none)

References

(none)