ID: 32738
User updated by: pvandijk at gmail dot com
Reported By: pvandijk at gmail dot com
Status: Bogus
Bug Type: Reproducible crash
Operating System: Linux 2.4.22-1.2115.nptl
PHP Version: 4.3.11
New Comment:
Perhaps the reason i was unable to find the previous error reports is
that they seem to date back to 2002.
If this is indeed the same issue as Bug #16149 then i'm a little
puzzled as to why it hasnt been fixed over the past 3 years. maybe the
issue is more complex than just changing the ushort refcount, to a uint
in the _zval_struct?
Previous Comments:
------------------------------------------------------------------------
[2005-04-18 08:42:31] [EMAIL PROTECTED]
Please do not submit the same bug more than once. An existing
bug report already describes this very problem. Even if you feel
that your issue is somewhat different, the resolution is likely
to be the same.
Thank you for your interest in PHP.
This is because we have a 2 byte refcount counter. You're adding too
many (internal) references to $data overflowing the counter. When it
hits zero the data is free and you can't access it anymore - resulting
in the segfault.
------------------------------------------------------------------------
[2005-04-18 02:50:16] pvandijk at gmail dot com
Description:
------------
Hashes with a large number of keys and large key data size seem to
cause memory corruption, which in turn causes php to either segfault or
hang upon exiting (depending on the context of the code).
I've heard mention that arrays are not unlimited in size. This issue
seems to occur at about 65535 elements in my tests, but also depends on
the size of the keys. Presumably this is because i'm indexing my arrays
with Strings, and therefore it's running out of memory faster.
If the memory limit of a hash is reached, should it not be handled more
gracefully than corrupting memory, which results in a segfault?
The code example i've provided seems to reproduce a crash under both
linux and windows, php 4.3.11
Reproduce code:
---------------
<?php
$data = 'hello, i like cheese';
$ar = array();
for($i = 1000000; $i < 3000000 ; $i++) {
$key = 'abc'.$i;
$ar[$key] = $data;
}
function check($ar) {
global $data;
foreach($ar as $k => $value) {
if($data != $value) {
print 'invalid value: '. $k .' => '. $value ."\r\n";
}
}
}
check($ar);
print 'done.'."\r\n";
?>
Expected result:
----------------
done.
Actual result:
--------------
"done.
Segmentation fault"
sorry i cant provide a backtrace or any further info, i dont have
access to these tools on my current dev server.
------------------------------------------------------------------------
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Edit this bug report at http://bugs.php.net/?id=32738&edit=1
