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Bug #80173 Using return value of zend_assign_to_variable() is not safe
Submitted: 2020-10-02 10:33 UTC Modified: -
Votes:1
Avg. Score:1.0 ± 0.0
Reproduced:0 of 0 (0.0%)
From: nikic@php.net Assigned:
Status: Closed Package: Scripting Engine problem
PHP Version: 7.4.11 OS:
Private report: No CVE-ID: None
 [2020-10-02 10:33 UTC] nikic@php.net
Description:
------------
Reduced from oss-fuzz #25840:

<?php           
$a = new stdClass; 
$a->a =& $a;
var_dump($a->a = 0);

zend_assign_to_variable() returns variable_ptr, which might be destroyed by the assignment.

The root cause here is the same as in bug #80100, but the reproducer is more fundamental.

Probably the only way to address this is to add a separate version of zend_assign_to_variable() that accepts a zval to copy the value into, and perform that copy before disposing garbage.


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 [2021-07-02 08:09 UTC] git@php.net
Automatic comment on behalf of nikic
Revision: https://github.com/php/php-src/commit/bdc60fa7da65d29ac603dd32f3824abf9e71f65f
Log: Fixed bug #80173
 [2021-07-02 08:09 UTC] git@php.net
-Status: Open +Status: Closed
 
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