Add optional depth parameter to json_encode #62369

Author: winks

ext/json/json.c

@@ -47,6 +47,7 @@ ZEND_DECLARE_MODULE_GLOBALS(json)
 ZEND_BEGIN_ARG_INFO_EX(arginfo_json_encode, 0, 0, 1)
 	ZEND_ARG_INFO(0, value)
 	ZEND_ARG_INFO(0, options)
+	ZEND_ARG_INFO(0, depth)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_json_decode, 0, 0, 1)
@@ -126,6 +127,7 @@ static PHP_GINIT_FUNCTION(json)
 {
 	json_globals->encoder_depth = 0;
 	json_globals->error_code = 0;
+	json_globals->encode_max_depth = 0;
 }
 /* }}} */
 
@@ -341,6 +343,9 @@ static void json_encode_array(smart_str *buf, zval **val, int options TSRMLS_DC)
 		}
 	}
 
+	if (JSON_G(encoder_depth) > JSON_G(encode_max_depth)) {
+		JSON_G(error_code) = PHP_JSON_ERROR_DEPTH;
+	}
 	--JSON_G(encoder_depth);
 	json_pretty_print_char(buf, options, '\n' TSRMLS_CC);
 	json_pretty_print_indent(buf, options TSRMLS_CC);
@@ -702,13 +707,16 @@ static PHP_FUNCTION(json_encode)
 	zval *parameter;
 	smart_str buf = {0};
 	long options = 0;
+    long depth = JSON_PARSER_DEFAULT_DEPTH;
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z|l", &parameter, &options) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "z|ll", &parameter, &options, &depth) == FAILURE) {
 		return;
 	}
 
 	JSON_G(error_code) = PHP_JSON_ERROR_NONE;
 
+	JSON_G(encode_max_depth) = depth;
+
 	php_json_encode(&buf, parameter, options TSRMLS_CC);
 
 	if (JSON_G(error_code) != PHP_JSON_ERROR_NONE && !(options & PHP_JSON_PARTIAL_OUTPUT_ON_ERROR)) {

ext/json/php_json.h

@@ -40,6 +40,7 @@ extern zend_module_entry json_module_entry;
 ZEND_BEGIN_MODULE_GLOBALS(json)
 	int encoder_depth;
 	int error_code;
+	int encode_max_depth;
 ZEND_END_MODULE_GLOBALS(json)
 
 #ifdef ZTS

ext/json/tests/bug62369.phpt

@@ -0,0 +1,34 @@
+--TEST--
+FR #62369 (Segfault on json_encode(deeply_nested_array)
+--SKIPIF--
+<?php if (!extension_loaded("json")) print "skip"; ?>
+--FILE--
+<?php
+
+$array = array();
+for ($i=0; $i<550; $i++) {
+    $array = array($array);
+}
+
+json_encode($array, 0, 551);
+switch (json_last_error()) {
+    case JSON_ERROR_NONE:
+        echo 'OK'.PHP_EOL;
+    break;
+    case JSON_ERROR_DEPTH:
+        echo 'ERROR'.PHP_EOL;
+    break;
+}
+
+json_encode($array, 0, 540);
+switch (json_last_error()) {
+    case JSON_ERROR_NONE:
+        echo 'OK'.PHP_EOL;
+    break;
+    case JSON_ERROR_DEPTH:
+        echo 'ERROR'.PHP_EOL;
+    break;
+}
+--EXPECTF--
+OK
+ERROR