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Bug #71756 Call-by-reference widens scope to uninvolved functions when used in switch
Submitted: 2016-03-09 14:16 UTC Modified: 2016-03-10 07:12 UTC
Votes:1
Avg. Score:4.0 ± 0.0
Reproduced:1 of 1 (100.0%)
Same Version:1 (100.0%)
Same OS:1 (100.0%)
From: lang at six dot de Assigned: laruence
Status: Closed Package: Variables related
PHP Version: 7.0.4 OS: Linux 7afb14e6ee75 3.16.7-35-des
Private report: No CVE-ID:
 [2016-03-09 14:16 UTC] lang at six dot de
Description:
------------
Under very certain circumstances a call-by-reference gets out of bounds. A cascaded call of functions, where one of them has a call-by-reference in its parameters, a change to a copy of an hash gets unexpectedly overwritten outside of its scope. Key to this behaviour is the use of the switch-statement in the final function call.

Additional Information:
- casting the switch-parameter to string solves the problem
- changing the switch into an if-statement also solves the problem

Test script:
---------------
<?php
function a ($option) {
        b($option['bla']);
        c($option);
var_dump($option);
}
function b (&$string) {
        $string = 'changed';
}
function c ($option) {
        switch ($option['bla']) {
                case 'changed':
                        $copy = $option;
                        $copy['bla'] = 'copy';
                        break;
        }
}
a(array('bla' => 'fasel'));

Expected result:
----------------
array(1) { ["bla"]=> string(4) "changed" }

Actual result:
--------------
array(1) { ["bla"]=> string(4) "copy" }

Patches

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History

AllCommentsChangesGit/SVN commitsRelated reports
 [2016-03-10 07:12 UTC] laruence@php.net
-Status: Open +Status: Closed -Assigned To: +Assigned To: laruence
 [2016-03-10 07:12 UTC] laruence@php.net
The fix for this bug has been committed.

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will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.

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http://windows.php.net/snapshots/
 
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