Bug #55703 [Dup]: PHP crash when calling mysqli_fetch_fields
Edit report at https://bugs.php.net/bug.php?id=55703&edit=1
ID: 55703
Updated by: laruence@php.net
Reported by: eran at zend dot com
Summary: PHP crash when calling mysqli_fetch_fields
Status: Duplicate
Type: Bug
Package: MySQLi related
Operating System: Linux Ubuntu 11.04
PHP Version: 5.3.8
-Assigned To:
+Assigned To: laruence
Block user comment: N
Private report: N
New Comment:
in that case, then change it to always be "def" is okey, thanks :)
Previous Comments:
------------------------------------------------------------------------
[2011-09-16 19:41:02] eran at zend dot com
Agreed. Same crash as #55662
Can you apply the attached patch? The patch simply avoids accessing the uninitialized pointer and
sets the value to "def" (which like I mentioned in my previous post, is always the correct
value,
see here: http://dev.mysql.com/doc/refman/5.0/en/c-api-data-structures.html)
------------------------------------------------------------------------
[2011-09-16 08:51:07] laruence@php.net
plz look at #55662. anyway seems not only "explain" statement cause this segfault
------------------------------------------------------------------------
[2011-09-15 15:12:16] eran at zend dot com
Description:
------------
Hi,
Running the attached test script causes a crash in mysqli extension (in every
run).
The crash comes from mysqli_api.c, at around line 1058:
add_property_string(value, "catalog", (field->catalog ? field->catalog :
""),
1);
The member field->catalog contains an address to an uninitialized pointer.
Debugging libmysqlclient (self compiled, v5.1.58) shows that
libmysqlclient simply left this member uninitialized, thus pointing to an
uninitialized memory.
To work around this bug, I modified my PHP sources locally so the "catalog"
value is always set to "def" (which according to the documentation
http://dev.mysql.com/doc/refman/5.0/en/c-api-data-structures.html
is always
true)
(I also had a patch for libmysqlclient, but I am not sure where to send it...)
This crash is reproducible in CLI mode using the test script attached.
Attached is the patch to mysqli extension as well.
Test script:
---------------
<?php
$host = '127.0.0.1';
$user = 'user';
$pass = 'password';
$db = 'mydb';
$port = 3306;
$link = mysqli_init();
if (mysqli_real_connect($link, $host, $user, $pass, $db, $port)) {
$stmt = mysqli_stmt_init($link);
if(mysqli_stmt_prepare($stmt, "show processlist")) {
$res = mysqli_stmt_execute($stmt);
$res_set = mysqli_stmt_result_metadata($stmt);
var_dump ( $res_set );
var_dump(mysqli_fetch_fields( $res_set ));
}
}
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=55703&edit=1
Thread (5 messages)