(RHSA-2015:1447) Low: grep security, bug fix, and enhancement update

The grep utility searches through textual input for lines that contain a
match to a specified pattern and then prints the matching lines. The GNU
grep utilities include grep, egrep, and fgrep.

An integer overflow flaw, leading to a heap-based buffer overflow, was
found in the way grep parsed large lines of data. An attacker able to trick
a user into running grep on a specially crafted data file could use this
flaw to crash grep or, potentially, execute arbitrary code with the
privileges of the user running grep. (CVE-2012-5667)

A heap-based buffer overflow flaw was found in the way grep processed
certain pattern and text combinations. An attacker able to trick a user
into running grep on specially crafted input could use this flaw to crash
grep or, potentially, read from uninitialized memory. (CVE-2015-1345)

The grep packages have been upgraded to upstream version 2.20, which
provides a number of bug fixes and enhancements over the previous version.
Notably, the speed of various operations has been improved significantly.
Now, the recursive grep utility uses the fts function of the gnulib library
for directory traversal, so that it can handle much larger directories
without reporting the “File name too long” error message, and it can
operate faster when dealing with large directory hierarchies. (BZ#982215,
BZ#1064668, BZ#1126757, BZ#1167766, BZ#1171806)

This update also fixes the following bugs:

• Prior to this update, the \w and \W symbols were inconsistently matched
  to the [:alnum:] character class. Consequently, regular expressions that used \w
  and \W in some cases had incorrect results. An upstream patch which fixes the
  matching problem has been applied, and \w is now matched to the [[:alnum:]]
  character and \W to the [^[:alnum:]] character consistently. (BZ#799863)

• Previously, the “–fixed-regexp” command-line option was not included in
  the grep(1) manual page. Consequently, the manual page was inconsistent
  with the built-in help of the grep utility. To fix this bug, grep(1) has
  been updated to include a note informing the user that “–fixed-regexp” is
  an obsolete option. Now, the built-in help and manual page are consistent
  regarding the “–fixed-regexp” option. (BZ#1103270)

• Previously, the Perl Compatible Regular Expression (PCRE) library did not
  work correctly when matching non-UTF-8 text in UTF-8 mode. Consequently, an
  error message about invalid UTF-8 byte sequence characters was returned.
  To fix this bug, patches from upstream have been applied to the PCRE
  library and the grep utility. As a result, PCRE now skips non-UTF-8
  characters as non-matching text without returning any error message.
  (BZ#1193030)

All grep users are advised to upgrade to these updated packages, which
correct these issues and add these enhancements.