Bug #55703 [Dup->Csd]: 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 +Status: Closed Type: Bug Package: MySQLi related Operating System: Linux Ubuntu 11.04 PHP Version: 5.3.8 Assigned To: laruence Block user comment: N Private report: N New Comment: This bug has been fixed in SVN. Snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. For Windows: http://windows.php.net/snapshots/ Thank you for the report, and for helping us make PHP better. Previous Comments: ------------------------------------------------------------------------ [2011-09-17 03:12:06] laruence@php.net Automatic comment from SVN on behalf of laruence Revision: http://svn.php.net/viewvc/?view=revision&amp;revision=316895 Log: Fix Bug #55703(PHP crash when calling mysqli_fetch_fields) Since the catalog values always is &quot;def&quot; now, see http://dev.mysql.com/doc/refman/5.0/en/c-api-data-structures.html ------------------------------------------------------------------------ [2011-09-17 02:58:29] laruence@php.net in that case, then change it to always be "def" is okey, thanks :) ------------------------------------------------------------------------ [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