util: do not rely on mutable Object and Function' constructor prop

lib/internal/util/inspect.js

@@ -22,8 +22,11 @@ const {
   DatePrototypeToISOString,
   DatePrototypeToString,
   ErrorPrototypeToString,
+  Function,
+  FunctionPrototype,
   FunctionPrototypeBind,
   FunctionPrototypeCall,
+  FunctionPrototypeSymbolHasInstance,
   FunctionPrototypeToString,
   JSONStringify,
   MapPrototypeEntries,
@@ -50,6 +53,7 @@ const {
   ObjectGetPrototypeOf,
   ObjectIs,
   ObjectKeys,
+  ObjectPrototype,
   ObjectPrototypeHasOwnProperty,
   ObjectPrototypePropertyIsEnumerable,
   ObjectSeal,
@@ -593,10 +597,26 @@ function isInstanceof(object, proto) {
   }
 }
 
+// Special-case for some builtin prototypes in case their `constructor` property has been tampered.
+const wellKnownPrototypes = new SafeMap();
+wellKnownPrototypes.set(ObjectPrototype, { name: 'Object', constructor: Object });
+wellKnownPrototypes.set(FunctionPrototype, { name: 'Function', constructor: Function });
+
 function getConstructorName(obj, ctx, recurseTimes, protoProps) {
   let firstProto;
   const tmp = obj;
   while (obj || isUndetectableObject(obj)) {
+    const wellKnownPrototypeNameAndConstructor = wellKnownPrototypes.get(obj);
+    if (wellKnownPrototypeNameAndConstructor != null) {
+      const { name, constructor } = wellKnownPrototypeNameAndConstructor;
+      if (FunctionPrototypeSymbolHasInstance(constructor, tmp)) {
+        if (protoProps !== undefined && firstProto !== obj) {
+          addPrototypeProperties(
+            ctx, tmp, firstProto || tmp, recurseTimes, protoProps);
+        }
+        return name;
+      }
+    }
     const descriptor = ObjectGetOwnPropertyDescriptor(obj, 'constructor');
     if (descriptor !== undefined &&
         typeof descriptor.value === 'function' &&
@@ -954,7 +974,11 @@ function formatRaw(ctx, value, recurseTimes, typedArray) {
   if (noIterator) {
     keys = getKeys(value, ctx.showHidden);
     braces = ['{', '}'];
-    if (constructor === 'Object') {
+    if (typeof value === 'function') {
+      base = getFunctionBase(value, constructor, tag);
+      if (keys.length === 0 && protoProps === undefined)
+        return ctx.stylize(base, 'special');
+    } else if (constructor === 'Object') {
       if (isArgumentsObject(value)) {
         braces[0] = '[Arguments] {';
       } else if (tag !== '') {
@@ -963,10 +987,6 @@ function formatRaw(ctx, value, recurseTimes, typedArray) {
       if (keys.length === 0 && protoProps === undefined) {
         return `${braces[0]}}`;
       }
-    } else if (typeof value === 'function') {
-      base = getFunctionBase(value, constructor, tag);
-      if (keys.length === 0 && protoProps === undefined)
-        return ctx.stylize(base, 'special');
     } else if (isRegExp(value)) {
       // Make RegExps say that they are RegExps
       base = RegExpPrototypeToString(

test/parallel/test-util-inspect.js

@@ -3355,3 +3355,33 @@ assert.strictEqual(
     '}',
   );
 }
+
+{
+  const o = {};
+  const { prototype: BuiltinPrototype } = Object;
+  const desc = Reflect.getOwnPropertyDescriptor(BuiltinPrototype, 'constructor');
+  Object.defineProperty(BuiltinPrototype, 'constructor', {
+    get: () => BuiltinPrototype,
+    configurable: true,
+  });
+  assert.strictEqual(
+    util.inspect(o),
+    '{}',
+  );
+  Object.defineProperty(BuiltinPrototype, 'constructor', desc);
+}
+
+{
+  const o = { f() {} };
+  const { prototype: BuiltinPrototype } = Function;
+  const desc = Reflect.getOwnPropertyDescriptor(BuiltinPrototype, 'constructor');
+  Object.defineProperty(BuiltinPrototype, 'constructor', {
+    get: () => BuiltinPrototype,
+    configurable: true,
+  });
+  assert.strictEqual(
+    util.inspect(o),
+    '{ f: [Function: f] }',
+  );
+  Object.defineProperty(BuiltinPrototype, 'constructor', desc);
+}