Bug #79235 [NEW]: Large consumption of memory when using a user filter

From: thomas dot gerbet at enalean dot com Operating system: Linux PHP version: 7.3.14 Package: Streams related Bug Type: Bug Bug description:Large consumption of memory when using a user filter Description: ------------ Since PHP 7.3.11 (it looks like it is the case since https://github.com/php/php-src/commit/05560b67bc87a2bcbfd5b48a48443a62f3311e7d) processing a stream with a PHP user filter consumes at least the same amount of memory that the size of the processed data. It was not the case before. Test script: --------------- <?php $input_resource = fopen('/dev/zero', 'rb'); $dev_null = fopen('/dev/null', 'wb+'); class TestFilter extends \php_user_filter { public function filter($in, $out, &$consumed, $closing) { while ($bucket = \stream_bucket_make_writeable($in)) { $consumed += $bucket->datalen; \stream_bucket_append($out, $bucket); } return PSFS_PASS_ON; } } \stream_filter_register('testm', \TestFilter::class); $input_with_filter = \stream_filter_prepend( $input_resource, 'testm', STREAM_FILTER_READ ); stream_copy_to_stream($input_resource, $dev_null, 1 * 1024 * 1024 * 1024); fclose($dev_null); fclose($input_resource); Expected result: ---------------- // No fatal error Actual result: -------------- PHP Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 65019904 bytes) in example.php on line 24 -- Edit bug report at https://bugs.php.net/bug.php?id=79235&edit=1 -- Fix committed: https://bugs.php.net/fix.php?id=79235&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=79235&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=79235&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=79235&r=needscript Try newer version: https://bugs.php.net/fix.php?id=79235&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=79235&r=support Expected behavior: https://bugs.php.net/fix.php?id=79235&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=79235&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=79235&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=79235&r=globals PHP version support discontinued: https://bugs.php.net/fix.php?id=79235&r=phptooold Daylight Savings: https://bugs.php.net/fix.php?id=79235&r=dst IIS Stability: https://bugs.php.net/fix.php?id=79235&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=79235&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=79235&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=79235&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=79235&r=mysqlcfg