#32508 [Opn->Fbk]: ob_gzhandler w/ chunking can crash Apache 2

ID: 32508 Updated by: sniper@php.net Reported By: myronwu at gmail dot com -Status: Open +Status: Feedback Bug Type: Output Control Operating System: Linux 2.4 PHP Version: 5.0.3 New Comment: You can always make the chunk size smaller than 2048? Or doesn't this problem occur then? Previous Comments: ------------------------------------------------------------------------ [2005-03-31 08:33:29] myronwu at gmail dot com Sorry, it's my sysadmin that set up those configure variables.... Anyway, we used phpinfo() for example code because it outputs something larger than the example chunk size I was using of 2048 bytes. I could manually write out more than 2048, but that probably wouldn't be as concise for bug reporting. The problem we have specifically arises when the ob_gzhandler attempts to send out chunks. ------------------------------------------------------------------------ [2005-03-31 08:20:56] sniper@php.net Does it only happen when you have phpinfo() in there? (I'd put something else between there..) Also, try doing ./configure --help sometimes. You have several options used that don't even exist. Like --enable-track-vars, --with-apache2.. ------------------------------------------------------------------------ [2005-03-31 02:15:34] myronwu at gmail dot com Reconfirmed the bug using the reproduce code on CVS snapshot php5-STABLE-200503302230, configure command: './configure' '--with-mysqli=/usr/local/mysql/bin/mysql_config' '--with-mysql=/usr/local/mysql' '--with-apache2=/usr/src/apache/httpd-2.0.53' '--enable-yp' '--enable-track-vars' '--with-zlib' '--with-jpeg' '--with-png' '--with-tiff' '--with-pdflib' '--with-gd' '--with-apxs2=/var/www/bin/apxs' '--with-gettext' '--with-pspell' Otherwise same setup as reported above. ------------------------------------------------------------------------ [2005-03-30 22:44:12] tony2001@php.net Please try using this CVS snapshot: http://snaps.php.net/php5-STABLE-latest.tar.gz For Windows: http://snaps.php.net/win32/php5.0-win32-latest.zip ------------------------------------------------------------------------ [2005-03-30 22:38:41] myronwu at gmail dot com Description: ------------ In certain browsers, attempting to output data before a call to ob_start('ob_gzhandler', chunk_size) causes Apache 2 to consume huge (all) amounts of memory. This only occurs when chunking takes place (ie size of data output > chunk_size). Outputting data before a call to ob_start without a chunk_size or without 'ob_gzhandler' works as expected. Browsers tested that were affected: Firefox, Opera Browsers tested that were unaffected: Links Diff between php.ini and php.ini-dist: register_globals = On Apache version: Apache/2.0.53 (Unix) mod_ssl/2.0.53 OpenSSL/0.9.7a PHP/ 5.0.3 using prefork mpm. Zlib version: 1.1.4 PHP configure command: './configure' '--with-mysqli=/usr/local/mysql/bin/ mysql_config' '--with-mysql=/usr/local/mysql' '--with- apache2=/usr/src/apache/httpd-2.0.53' '--enable-yp' '-- enable-track-vars' '--with-zlib' '--with-jpeg' '--with- png' '--with-tiff' '--with-pdflib' '--with-gd' '--with- apxs2=/var/www/bin/apxs' '--with-gettext' '--with- pspell' This was also reproduced on another box with the same versions of Apache 2, zlib, but PHP 4.3.1 with configure command: './configure' '--with-mysql=/usr/local/mysql' '--with- apache2=/usr/src/httpd-2.0.46' '--enable-yp' '--enable- track-vars' '--with-zlib-dir=/usr/local/lib' '--with- jpeg-dir=/usr/local/lib' '--with-png-dir=/usr/local/lib' '--with-tiff-dir=/usr/local/lib' '--with-pdflib' '-- with-gd=yes' '--with-apxs2=/var/www/bin/apxs' Reproduce code: --------------- <?php echo 'test!'; ob_start('ob_gzhandler', 2048); phpinfo(); ob_end_flush(); ?> Expected result: ---------------- test! (phpinfo() output) Actual result: -------------- Nothing. The browser doesn't receive any information to display and httpd begins to consume all available memory. ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=32508&edit=1