util: fix infinite recursion during inspection

A specially crafted object with circular structures behind getters could cause a infinite recursion. This is now fixed by detecting the objects as already visited. Signed-off-by: Ruben Bridgewater <[email protected]> PR-URL: #37079Fixes: #37054 Reviewed-By: James M Snell <[email protected]> Reviewed-By: Rich Trott <[email protected]> Reviewed-By: Juan José Arboleda <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Anto Aravinth <[email protected]> Reviewed-By: Trivikram Kamat <[email protected]>

Author: BridgeAR

lib/internal/util/inspect.js

@@ -5,6 +5,7 @@ const{
  ArrayIsArray,
  ArrayPrototypeFilter,
  ArrayPrototypeForEach,
+ ArrayPrototypePop,
  ArrayPrototypePush,
  ArrayPrototypePushApply,
  ArrayPrototypeSort,
@@ -620,6 +621,7 @@ function addPrototypeProperties(ctx, main, obj, recurseTimes, output){
 }
 // Get all own property names and symbols.
 keys=ReflectOwnKeys(obj);
+ArrayPrototypePush(ctx.seen,main);
 for(constkeyofkeys){
 // Ignore the `constructor` property and keys that exist on layers above.
 if(key==='constructor'||
@@ -640,6 +642,7 @@ function addPrototypeProperties(ctx, main, obj, recurseTimes, output){
 ArrayPrototypePush(output,value);
 }
 }
+ArrayPrototypePop(ctx.seen);
 // Limit the inspection to up to three prototype layers. Using `recurseTimes`
 // is not a good choice here, because it's as if the properties are declared
 // on the current object from the users perspective.

test/parallel/test-util-inspect-getters-accessing-this.js

@@ -7,24 +7,61 @@ require('../common');
 
 constassert=require('assert');
 
-constutil=require('util');
+const{ inspect }=require('util');
 
-classX{
-constructor(){
-this._y=123;
-}
+{
+classX{
+constructor(){
+this._y=123;
+}
 
-gety(){
-returnthis._y;
+gety(){
+returnthis._y;
+}
 }
+
+constresult=inspect(newX(),{
+getters: true,
+showHidden: true
+});
+
+assert.strictEqual(
+result,
+'X{_y: 123, [y]: [Getter: 123] }'
+);
 }
 
-constresult=util.inspect(newX(),{
-getters: true,
-showHidden: true
-});
+// Regression test for https://github.com/nodejs/node/issues/37054
+{
+classA{
+constructor(B){
+this.B=B;
+}
+getb(){
+returnthis.B;
+}
+}
+
+classB{
+constructor(){
+this.A=newA(this);
+}
+geta(){
+returnthis.A;
+}
+}
+
+constresult=inspect(newB(),{
+depth: 1,
+getters: true,
+showHidden: true
+});
 
-assert.strictEqual(
-result,
-'X{_y: 123, [y]: [Getter: 123] }'
-);
+assert.strictEqual(
+result,
+'<ref *1> B{\n'+
+' A: A{B: [Circular *1], [b]: [Getter] [Circular *1] },\n'+
+' [a]: [Getter] A{B: [Circular *1], [b]: [Getter] [Circular *1] }\n'+
+'}',
+);
+}