#38543 [NEW]: shutdown_executor() may segfault when memory_limit is too low

From: tony2001@php.net Operating system: Linux PHP version: 5.2.0RC2 PHP Bug Type: Scripting Engine problem Bug description: shutdown_executor() may segfault when memory_limit is too low Description: ------------ PHP segfaults when memory_limit is too low (like 1 byte). The problem is that shutdown_executor() doesn't expect global hashes to be NULL and tries to destroy/free them, which leads to segfault. It's not a problem to add required if()'s, but we'd have to add them in places which are used very often (like zend_hash_*() funcs) and this may affect performance. Reproducible with both 5_2 and HEAD branches. Reproduce code: --------------- php.ini: memory_limit=1 php -r 'echo "ok\n";' Expected result: ---------------- ok Actual result: -------------- Fatal error: Allowed memory size of 1 bytes exhausted at /local/dev/php-src_5_2/Zend/zend_ini.c:246 (tried to allocate 2 bytes) in Unknown on line 0 [Tue Aug 22 13:51:18 2006] Script: '-' --------------------------------------- /local/dev/php-src_5_2/Zend/zend_hash.c(646) : Block 0x00000000 status: NULL --------------------------------------- Program received signal SIGSEGV, Segmentation fault. 0x08180729 in _zend_is_inconsistent (ht=0x0, file=0x8259438 "/local/dev/php-src_5_2/Zend/zend_hash.c", line=727) at /local/dev/php-src_5_2/Zend/zend_hash.c:53 53 if (ht->inconsistent==HT_OK) { (gdb) bt #0 0x08180729 in _zend_is_inconsistent (ht=0x0, file=0x8259438 "/local/dev/php-src_5_2/Zend/zend_hash.c", line=727) at /local/dev/php-src_5_2/Zend/zend_hash.c:53 #1 0x08182468 in zend_hash_reverse_apply (ht=0x0, apply_func=0x816efa7 <zend_cleanup_function_data>) at /local/dev/php-src_5_2/Zend/zend_hash.c:727 #2 0x0816a988 in shutdown_executor () at /local/dev/php-src_5_2/Zend/zend_execute_API.c:275 #3 0x08177d1b in zend_deactivate () at /local/dev/php-src_5_2/Zend/zend.c:839 #4 0x08130e35 in php_request_shutdown (dummy=0x0) at /local/dev/php-src_5_2/main/main.c:1300 #5 0x081de00c in main (argc=3, argv=0xbfffefe4) at /local/dev/php-src_5_2/sapi/cli/php_cli.c:1250 -- Edit bug report at http://bugs.php.net/?id=38543&edit=1 -- Try a CVS snapshot (PHP 4.4): http://bugs.php.net/fix.php?id=38543&r=trysnapshot44 Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=38543&r=trysnapshot52 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=38543&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=38543&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=38543&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=38543&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=38543&r=needscript Try newer version: http://bugs.php.net/fix.php?id=38543&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=38543&r=support Expected behavior: http://bugs.php.net/fix.php?id=38543&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=38543&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=38543&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=38543&r=globals PHP 3 support discontinued: http://bugs.php.net/fix.php?id=38543&r=php3 Daylight Savings: http://bugs.php.net/fix.php?id=38543&r=dst IIS Stability: http://bugs.php.net/fix.php?id=38543&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=38543&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=38543&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=38543&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=38543&r=mysqlcfg