From: wmeler at wp dot pl
Operating system: Linux
PHP version: 5.1.5CVS
PHP Bug Type: Scripting Engine problem
Bug description: zend_ptr_stack reallocation problem
Description:
------------
Argument stack reallocations may cause heap corruption or segmentation
faults.
Functions that accept arguments through zend_get_parameters (zval ** -
pointer to zend_ptr_stack element) and running user callbacks that may
need more stack space are affected.
So unserialize (__wakeup), sort functions in 4.4 version, and so on.
Also using complicated user error handler is quite risky.
Reproduce code:
---------------
<?
class test {
function extend_zend_ptr_stack($count,$a,$b,$c,$d,$e) {
if ($count>0) $this->extend_zend_ptr_stack($count -
1,$a,$b,$c,$d,$e);
}
function __wakeup() {
$this->extend_zend_ptr_stack(10,'a','b','c','d','e');
}
}
$str='a:2:{i:0;O:4:"test":0:{}junk';
var_dump(unserialize($str));
Expected result:
----------------
bool(false)
Actual result:
--------------
#0 0x081be837 in zif_unserialize (ht=1, return_value=0x9b97ddc,
return_value_ptr=0x0, this_ptr=0x0, return_value_used=1) at
/root/cvs/php_5_1/ext/standard/var.c:860
#1 0x08234f10 in zend_do_fcall_common_helper_SPEC
(execute_data=0xbfec6c80) at /root/cvs/php_5_1/Zend/zend_vm_execute.h:192
#2 0x082348a1 in execute (op_array=0x9ba611c) at
/root/cvs/php_5_1/Zend/zend_vm_execute.h:92
#3 0x0821acb2 in zend_execute_scripts (type=8, retval=0x0, file_count=3)
at /root/cvs/php_5_1/Zend/zend.c:1101
#4 0x081e2804 in php_execute_script (primary_file=0xbfec9180) at
/root/cvs/php_5_1/main/main.c:1719
#5 0x08285f9e in main (argc=2, argv=0xbfec9254) at
/root/cvs/php_5_1/sapi/cli/php_cli.c:1090
--
Edit bug report at http://bugs.php.net/?id=37947&edit=1
--
Try a CVS snapshot (PHP 4.4):
http://bugs.php.net/fix.php?id=37947&r=trysnapshot44
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=37947&r=trysnapshot52
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=37947&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=37947&r=fixedcvs
Fixed in release:
http://bugs.php.net/fix.php?id=37947&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=37947&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=37947&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=37947&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=37947&r=support
Expected behavior: http://bugs.php.net/fix.php?id=37947&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=37947&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=37947&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=37947&r=globals
PHP 3 support discontinued: http://bugs.php.net/fix.php?id=37947&r=php3
Daylight Savings: http://bugs.php.net/fix.php?id=37947&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=37947&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=37947&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=37947&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=37947&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=37947&r=mysqlcfg
