From: bens at effortlessis dot com
Operating system: Fedora Core 1 Linux
PHP version: 4.3.6
PHP Bug Type: *Regular Expressions
Bug description: preg_match has severe memory leak
Description:
------------
I wrote a script to parse a sendmail log file to match records together by
message id in order to gather some statistics about a particular relay
situation.
When run, this script quickly swallowed all available RAM, bringing a
busy, production system to a standstill. I reduced the script to the
simplest code that causes the memory leak.
When run as "php -q scriptname.php /var/log/maillog" from the command
line, where maillog contains > 500,000 lines, this script will leak memory
until the system load average exceeds 5.0.
Rem out the preg_match on the innermost loop and the memory leak
disappears. This bug is found in 4.3.4 and 4.3.6, I haven't tested other
versions.
Reproduce code:
---------------
<?
set_time_limit(0);
// GETS $msgid;
$match="/\]\:\s+([0-9a-zA-Z]+)\:/";
if (!$file=trim($_SERVER['argv'][1]))
die('You must specify maillog file location');
if ($fp=fopen($file, 'r'))
{
while ($line=fgets($fp, 1024))
if (preg_match($match, $line, $r))
{
$msgid=trim($r[1]);
//$mfrom="/$msgid\:\s+from=\<*(.*?)[\s\>].*?relay=.*?\[([0-9\.]+)\]/";
$mfrom="/$msgid/";
// REM THIS LINE OUT AND THE MEMORY LEAK STOPS.
preg_match($mfrom, $line);
}
fclose($fp);
}
?>
Expected result:
----------------
The "top" command should show this PHP instance using < 10% of RAM on a 1
GB RAM system.
Actual result:
--------------
The "top" command shows > 99% of memory usage on a 1 GB system.
--
Edit bug report at http://bugs.php.net/?id=28513&edit=1
--
Try a CVS snapshot (php4): http://bugs.php.net/fix.php?id=28513&r=trysnapshot4
Try a CVS snapshot (php5): http://bugs.php.net/fix.php?id=28513&r=trysnapshot5
Fixed in CVS: http://bugs.php.net/fix.php?id=28513&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=28513&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=28513&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=28513&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=28513&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=28513&r=support
Expected behavior: http://bugs.php.net/fix.php?id=28513&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=28513&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=28513&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=28513&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=28513&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=28513&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=28513&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=28513&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=28513&r=float
