Bug #78525 [NEW]: Memory leak in pdo when reusing native prepared statements

From: victoria at sharksmedia dot dk Operating system: CentOS 7.6.1810 PHP version: 7.3.9 Package: PDO MySQL Bug Type: Bug Bug description:Memory leak in pdo when reusing native prepared statements Description: ------------ If a native prepared statement is reused, it will leak memory on each reuse. If the statement is prepared each time, there is no memory leak. All versions of PHP 7.2 works, and all versions of PHP 7.3 leaks memory. Versions: Percona MySQL 5.7 & 8.0 PHP 7.3.x Mysqlnd: mysqlnd 5.0.12-dev The call to closeCursor() doesn't change anything. Test script: --------------- $pdo = new \PDO('mysql:host=<host>;dbname=<dbname>', 'user', 'password'); $pdo->setAttribute(\PDO::ATTR_EMULATE_PREPARES, false); $stmt = $pdo->prepare('SELECT field FROM table LIMIT 100'); for($i=0;$i<250000;$i++) { $stmt->execute(); $stmt->fetchAll(); //$stmt->closeCursor(); if($i%1000 === 0) print memory_get_usage()."\r\n"; } Expected result: ---------------- PHP 7.2.22: 446824 446856 446856 446856 446856 446856 446856 446856 446856 446856 446856 446856 446856 446856 446856 Actual result: -------------- PHP 7.3.9: 479176 970728 1445864 1937384 2428904 2920424 3411944 3903464 4378600 4870120 5361640 5853160 6344680 6836200 7327720 -- Edit bug report at https://bugs.php.net/bug.php?id=78525&edit=1 -- Fix committed: https://bugs.php.net/fix.php?id=78525&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=78525&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=78525&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=78525&r=needscript Try newer version: https://bugs.php.net/fix.php?id=78525&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=78525&r=support Expected behavior: https://bugs.php.net/fix.php?id=78525&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=78525&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=78525&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=78525&r=globals PHP version support discontinued: https://bugs.php.net/fix.php?id=78525&r=phptooold Daylight Savings: https://bugs.php.net/fix.php?id=78525&r=dst IIS Stability: https://bugs.php.net/fix.php?id=78525&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=78525&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=78525&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=78525&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=78525&r=mysqlcfg