RHBA-2012:0385 - Bug Fix Advisory

Topic

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

Description

The gawk package contains the GNU version of awk, a text processing utility. AWK
interprets a special-purpose programming language to do quick and easy text
pattern matching and reformatting jobs.

This update fixes the following bugs:

• Prior to this update, the gawk utility could, under certain circumstances,

interpret some run-time variables as internal zero-length variable prototypes.
When gawk tried to free such run-time variables, it actually freed the internal
prototypes, that were allocated just once due to memory savings. As a
consequence, gawk sometimes failed and the error message "awk: double free or
corruption" was displayed. With this update the problem has been corrected and
the error no longer occurs. (BZ#648906)

• Prior to this update, the gawk utility did not copy variables from the command

line arguments. As a consequence, the variables were not accessible as intended.
This update modifies the underlying code so that gawk makes copies of those
variables. (BZ#740673)

• Prior to this update, the Yacc interpreter encountered problems handling

larger stacks. As a consequence, the Yacc interpreter could fail with a stack
overflow error when interpreting the AWK code. This update enlarges the stack
and Yacc can now handle these AWK programs. (BZ#743242)

All users of gawk are advised to upgrade to this updated package, which fixes
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/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 648906 - gawk regression from RHEL3/4
• BZ - 743242 - gawk + byacc = YACC Stack Overflow regression

CVEs

(none)

References

(none)