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/72433.diff Secret
Created Jun 21, 2016

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Patch for 72433
commit 3f627e580acfdaf0595ae3b115b8bec677f203ee
Author: Stanislav Malyshev <stas@php.net>
Date: Mon Jun 20 21:26:33 2016 -0700
Fixed ##72433: Use After Free Vulnerability in PHP's GC algorithm and unserialize
diff --git a/Zend/tests/gc_024.phpt b/Zend/tests/gc_024.phpt
index 9a2ceb8..ca78da6 100644
--- a/Zend/tests/gc_024.phpt
+++ b/Zend/tests/gc_024.phpt
@@ -13,5 +13,5 @@ var_dump(gc_collect_cycles());
echo "ok\n";
?>
--EXPECT--
-int(1)
+int(2)
ok
diff --git a/ext/spl/spl_array.c b/ext/spl/spl_array.c
index c89cf49..4e03c40 100644
--- a/ext/spl/spl_array.c
+++ b/ext/spl/spl_array.c
@@ -831,6 +831,16 @@ static HashTable* spl_array_get_debug_info(zval *obj, int *is_temp TSRMLS_DC) /*
}
/* }}} */
+static HashTable *spl_array_get_gc(zval *object, zval ***gc_data, int *gc_data_count TSRMLS_DC) /* {{{ */
+{
+ spl_array_object *intern = (spl_array_object*)zend_object_store_get_object(object TSRMLS_CC);
+
+ *gc_data = &intern->array;
+ *gc_data_count = 1;
+ return zend_std_get_properties(object);
+}
+/* }}} */
+
static zval *spl_array_read_property(zval *object, zval *member, int type, const zend_literal *key TSRMLS_DC) /* {{{ */
{
spl_array_object *intern = (spl_array_object*)zend_object_store_get_object(object TSRMLS_CC);
@@ -1961,6 +1971,7 @@ PHP_MINIT_FUNCTION(spl_array)
spl_handler_ArrayObject.get_properties = spl_array_get_properties;
spl_handler_ArrayObject.get_debug_info = spl_array_get_debug_info;
+ spl_handler_ArrayObject.get_gc = spl_array_get_gc;
spl_handler_ArrayObject.read_property = spl_array_read_property;
spl_handler_ArrayObject.write_property = spl_array_write_property;
spl_handler_ArrayObject.get_property_ptr_ptr = spl_array_get_property_ptr_ptr;
diff --git a/ext/standard/tests/strings/bug72433.phpt b/ext/standard/tests/strings/bug72433.phpt
new file mode 100644
index 0000000..3a2c897
--- /dev/null
+++ b/ext/standard/tests/strings/bug72433.phpt
@@ -0,0 +1,32 @@
+--TEST--
+Bug #72433: Use After Free Vulnerability in PHP's GC algorithm and unserialize
+--FILE--
+<?php
+// Fill any potential freed spaces until now.
+$filler = array();
+for($i = 0; $i < 100; $i++)
+ $filler[] = "";
+// Create our payload and unserialize it.
+$serialized_payload = 'a:3:{i:0;r:1;i:1;r:1;i:2;C:11:"ArrayObject":19:{x:i:0;r:1;;m:a:0:{}}}';
+$free_me = unserialize($serialized_payload);
+// We need to increment the reference counter of our ArrayObject s.t. all reference counters of our unserialized array become 0.
+$inc_ref_by_one = $free_me[2];
+// The call to gc_collect_cycles will free '$free_me'.
+gc_collect_cycles();
+// We now have multiple freed spaces. Fill all of them.
+$fill_freed_space_1 = "filler_zval_1";
+$fill_freed_space_2 = "filler_zval_2";
+var_dump($free_me);
+?>
+--EXPECTF--
+array(3) {
+ [0]=>
+ *RECURSION*
+ [1]=>
+ *RECURSION*
+ [2]=>
+ object(ArrayObject)#%d (1) {
+ ["storage":"ArrayObject":private]=>
+ *RECURSION*
+ }
+}
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