Issued:
2011-12-06
Updated:
2011-12-06

RHBA-2011:1686 - tcsh bug fix update

Synopsis

tcsh bug fix update

Type/Severity

Bug Fix Advisory (none)

Topic

An updated tcsh package that fixes various bugs is now available for Red Hat Enterprise Linux 6.

Description

Tcsh is an enhanced and compatible version of the C shell (csh). It is a command language interpreter, which can be used as an interactive login shell, as well as a shell script command processor.

This updated tcsh package includes fixes for the following bugs:

  • Under certain circumstances when using the cwd symbolic link, a null pointer may have been incorrectly dereferenced, causing the tcsh shell to terminate unexpectedly. With this update, the pointer is now checked properly and tcsh no longer crashes. (BZ#700309)

  • This package fixes the return value of the "status" (or "$?") variable in the case of pipelines and backquoted commands. The "anyerror" variable, which selects the behavior, has been added to retain backward compatibility. (BZ#658190)

  • If the tcsh shell redirected standard output to a child process using a pipe and this child process terminated, the shell tried to print a message to the already-closed pipe as a high-priority event that could never been finished. As a consequence, tcsh entered an infinite loop and consumed up to 100% of the CPU. To fix this issue, this error event is now removed from the event queue before the shell tries to write it to the broken pipe. As result, the parent process terminates ordinarily. (BZ#690356)

  • Prior to this update, the blkend() function was called redundantly in the tsch code. These calls had no effect on tcsh functionality and thus they have been removed. Tcsh functionality remains unchanged and the code is now more effective. (BZ#684063)

  • The tcsh shell allowed variables to named in incorrect formats, such as by allowing a variable name to begin with a digit. This issue has been fixed: variable names are now verified according to Unix variable-naming conventions. (BZ#672592)

All users of tcsh are advised to upgrade to this updated package, which resolves these issues.

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 This content is not included.https://access.redhat.com/kb/docs/DOC-11259

Affected Products

ProductVersionArch
Red Hat Enterprise Linux for Scientific Computing6x86_64
Red Hat Enterprise Linux for Power, big endian6ppc64
Red Hat Enterprise Linux for IBM z Systems6s390x
Red Hat Enterprise Linux Workstation6x86_64
Red Hat Enterprise Linux Workstation6i386
Red Hat Enterprise Linux Server6x86_64
Red Hat Enterprise Linux Server6i386
Red Hat Enterprise Linux Server from RHUI6x86_64
Red Hat Enterprise Linux Server from RHUI6i386
Red Hat Enterprise Linux Server - Extended Life Cycle Support6x86_64
Red Hat Enterprise Linux Server - Extended Life Cycle Support6i386
Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension6x86_64
Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension6i386
Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems)6s390x
Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems)6s390x
Red Hat Enterprise Linux Desktop6x86_64
Red Hat Enterprise Linux Desktop6i386

Updated Packages

  • tcsh-6.17-14.el6.src.rpm
  • tcsh-6.17-14.el6.x86_64.rpm
  • tcsh-debuginfo-6.17-14.el6.ppc64.rpm
  • tcsh-debuginfo-6.17-14.el6.s390x.rpm
  • tcsh-6.17-14.el6.ppc64.rpm
  • tcsh-debuginfo-6.17-14.el6.i686.rpm
  • tcsh-6.17-14.el6.i686.rpm
  • tcsh-debuginfo-6.17-14.el6.x86_64.rpm
  • tcsh-6.17-14.el6.s390x.rpm

Fixes

CVEs

(none)

References

(none)

Additional information