Fixed bug #67539 (ArrayIterator use-after-free due to object change during sorting)

NEWS

@@ -22,6 +22,8 @@ PHP                                                                        NEWS
     which affected builds against libpq < 7.3. (Adam)
 
 - SPL:
+  . Fixed bug #67539 (ArrayIterator use-after-free due to object change during 
+    sorting). (research at insighti dot org, Laruence)
   . Fixed bug #67538 (SPL Iterators use-after-free). (Laruence)
 
 - Streams:

ext/spl/spl_array.c

@@ -1733,6 +1733,7 @@ SPL_METHOD(Array, unserialize)
 	const unsigned char *p, *s;
 	php_unserialize_data_t var_hash;
 	zval *pmembers, *pflags = NULL;
+	HashTable *aht;
 	long flags;
 
 	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &buf, &buf_len) == FAILURE) {
@@ -1744,6 +1745,12 @@ SPL_METHOD(Array, unserialize)
 		return;
 	}
 
+	aht = spl_array_get_hash_table(intern, 0 TSRMLS_CC);
+	if (aht->nApplyCount > 0) {
+		zend_error(E_WARNING, "Modification of ArrayObject during sorting is prohibited");
+		return;
+	}
+
 	/* storage */
 	s = p = (const unsigned char*)buf;
 	PHP_VAR_UNSERIALIZE_INIT(var_hash);

ext/spl/tests/bug67539.phpt

@@ -0,0 +1,15 @@
+--TEST--
+Bug #67539 (ArrayIterator use-after-free due to object change during sorting)
+--FILE--
+<?php
+
+$it = new ArrayIterator(array_fill(0,2,'X'), 1 );
+
+function badsort($a, $b) {
+        $GLOBALS['it']->unserialize($GLOBALS['it']->serialize());
+        return TRUE;
+}
+
+$it->uksort('badsort');
+--EXPECTF--
+Warning: Modification of ArrayObject during sorting is prohibited in %sbug67539.php on line %d