util: protect against monkeypatched Object prototype for inspect()

Prevent affects of monkeypatching (for example) Object.keys() when calling util.inspect(). PR-URL: #25953 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
nodejs · Feb 5, 2019 · 1847696f4b6284bad45f452bc8595927074118dc · 1847696
1 parent ba4df92
commit 1847696f4b6284bad45f452bc8595927074118dc
Unified Split

Showing with 19 additions and 7 deletions.

+8 −7 lib/internal/util/inspect.js

+11 −0 test/parallel/test-util-primordial-monkeypatching.js
diff --git a/lib/internal/util/inspect.js b/lib/internal/util/inspect.js
@@ -63,6 +63,11 @@ const {
  isBigUint64Array
 } = require('internal/util/types');
+  
+const assert = require('internal/assert');
+  
+
+  
+// Avoid monkey-patched built-ins.
+  
+const { Object } = primordials;
+  
+
 const ReflectApply = Reflect.apply;
 // This function is borrowed from the function with the same name on V8 Extras'
@@ -383,13 +388,9 @@ function getKeys(value, showHidden) {
    try {
      keys = Object.keys(value);
    } catch (err) {
-  
-      if (isNativeError(err) &&
-  
-          err.name === 'ReferenceError' &&
-  
-          isModuleNamespaceObject(value)) {
-  
-        keys = Object.getOwnPropertyNames(value);
-  
-      } else {
-  
-        throw err;
-  
-      }
+  
+      assert(isNativeError(err) && err.name === 'ReferenceError' &&
+  
+             isModuleNamespaceObject(value));
+  
+      keys = Object.getOwnPropertyNames(value);
    }
    if (symbols.length !== 0) {
      keys.push(...symbols.filter((key) => propertyIsEnumerable(value, key)));

diff --git a/test/parallel/test-util-primordial-monkeypatching.js b/test/parallel/test-util-primordial-monkeypatching.js
@@ -0,0 +1,11 @@
+  
+'use strict';
+  
+
+  
+// Monkeypatch Object.keys() so that it throws an unexpected error. This tests
+  
+// that `util.inspect()` is unaffected by monkey-patching `Object`.
+  
+
+  
+require('../common');
+  
+const assert = require('assert');
+  
+const util = require('util');
+  
+
+  
+Object.keys = () => { throw new Error('fhqwhgads'); };
+  
+assert.strictEqual(util.inspect({}), '{}');