Fixed crash in usort() and uasort() in case user comparison function modifyes the...

diff --git a/ext/standard/array.c b/ext/standard/array.c
index 4604cdb942c5bf619bd0c27d805348063c2512b3..b834b08ffba0f4b488e3f4d95b46c9c27a911bef 100644 (file)
--- a/ext/standard/array.c
+++ b/ext/standard/array.c
@@ -657,6 +657,7 @@ static int array_user_compare(const void *a, const void *b TSRMLS_DC) /* {{{ */
 PHP_FUNCTION(usort)
 {
        zval **array;
+       int refcount;
        HashTable *target_hash;
        PHP_ARRAY_CMP_FUNC_VARS;
 
@@ -678,12 +679,31 @@ PHP_FUNCTION(usort)
        PHP_ARRAY_CMP_FUNC_CHECK(BG(user_compare_func_name))
        BG(user_compare_fci_cache).initialized = 0;
        
+       /* Clear the is_ref flag, so the attemts to modify the array in user
+        * comaprison function will create a copy of array and won't affect the
+        * original array. The fact of modification is detected using refcount
+        * comparison. The result of sorting in such case is undefined and the
+        * function returns FALSE.
+        */
+       (*array)->is_ref = 0;
+       refcount = (*array)->refcount;
+
        if (zend_hash_sort(target_hash, zend_qsort, array_user_compare, 1 TSRMLS_CC) == FAILURE) {
-               PHP_ARRAY_CMP_FUNC_RESTORE();
-               RETURN_FALSE;
+               RETVAL_FALSE;
+       } else {
+               if (refcount > (*array)->refcount) {
+                       php_error_docref(NULL TSRMLS_CC, E_WARNING, "Array was modified by the user comparison function");
+                       RETVAL_FALSE;
+               } else {
+                       RETVAL_TRUE;
+               }
+       }
+
+       if ((*array)->refcount > 1) {
+               (*array)->is_ref = 1;
        }
+       
        PHP_ARRAY_CMP_FUNC_RESTORE();
-       RETURN_TRUE;
 }
 /* }}} */
 
@@ -692,6 +712,7 @@ PHP_FUNCTION(usort)
 PHP_FUNCTION(uasort)
 {
        zval **array;
+       int refcount;
        HashTable *target_hash;
        PHP_ARRAY_CMP_FUNC_VARS;
 
@@ -711,13 +732,31 @@ PHP_FUNCTION(uasort)
        PHP_ARRAY_CMP_FUNC_CHECK(BG(user_compare_func_name))
        BG(user_compare_fci_cache).initialized = 0;
 
+       /* Clear the is_ref flag, so the attemts to modify the array in user
+        * comaprison function will create a copy of array and won't affect the
+        * original array. The fact of modification is detected using refcount
+        * comparison. The result of sorting in such case is undefined and the
+        * function returns FALSE.
+        */
+       (*array)->is_ref = 0;
+       refcount = (*array)->refcount;
+
        if (zend_hash_sort(target_hash, zend_qsort, array_user_compare, 0 TSRMLS_CC) == FAILURE) {
-               PHP_ARRAY_CMP_FUNC_RESTORE();
-               RETURN_FALSE;
+               RETVAL_FALSE;
+       } else {
+               if (refcount > (*array)->refcount) {
+                       php_error_docref(NULL TSRMLS_CC, E_WARNING, "Array was modified by the user comparison function");
+                       RETVAL_FALSE;
+               } else {
+                       RETVAL_TRUE;
+               }
        }
-       PHP_ARRAY_CMP_FUNC_RESTORE();
 
-       RETURN_TRUE;
+       if ((*array)->refcount > 1) {
+               (*array)->is_ref = 1;
+       }
+
+       PHP_ARRAY_CMP_FUNC_RESTORE();
 }
 /* }}} */