From 29faa41394e3cec75c22343a0b85bf72e20ae9c8 Mon Sep 17 00:00:00 2001
From: Joyee Cheung <joyeec9h3@gmail.com>
Date: Fri, 9 Feb 2018 01:22:37 +0800
Subject: [PATCH] fs: fix stack overflow in fs.readdirSync

Previously, fs.readdirSync calls the function returned by
env->push_values_to_array_function() in batch and check the returned
Maybe right away in C++, which can lead to assertions if the call stack
already reaches the maximum size. This patch fixes that by returning
early the call fails so the stack overflow error will be properly
thrown into JS land.
---
 src/node_file.cc                               | 12 +++++++++---
 .../parallel/test-fs-readdir-stack-overflow.js | 18 ++++++++++++++++++
 2 files changed, 27 insertions(+), 3 deletions(-)
 create mode 100644 test/parallel/test-fs-readdir-stack-overflow.js

diff --git a/src/node_file.cc b/src/node_file.cc
index 62dd5fe80cf8b2..e3a1da473111c1 100644
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -1132,14 +1132,20 @@ static void ReadDir(const FunctionCallbackInfo<Value>& args) {
       name_v[name_idx++] = filename.ToLocalChecked();
 
       if (name_idx >= arraysize(name_v)) {
-        fn->Call(env->context(), names, name_idx, name_v)
-            .ToLocalChecked();
+        MaybeLocal<Value> ret = fn->Call(env->context(), names, name_idx,
+                                         name_v);
+        if (ret.IsEmpty()) {
+          return;
+        }
         name_idx = 0;
       }
     }
 
     if (name_idx > 0) {
-      fn->Call(env->context(), names, name_idx, name_v).ToLocalChecked();
+      MaybeLocal<Value> ret = fn->Call(env->context(), names, name_idx, name_v);
+      if (ret.IsEmpty()) {
+        return;
+      }
     }
 
     args.GetReturnValue().Set(names);
diff --git a/test/parallel/test-fs-readdir-stack-overflow.js b/test/parallel/test-fs-readdir-stack-overflow.js
new file mode 100644
index 00000000000000..b7dea52cc37ec5
--- /dev/null
+++ b/test/parallel/test-fs-readdir-stack-overflow.js
@@ -0,0 +1,18 @@
+'use strict';
+
+const common = require('../common');
+
+const fs = require('fs');
+
+function recurse() {
+  fs.readdirSync('.');
+  recurse();
+}
+
+common.expectsError(
+  () => recurse(),
+  {
+    type: RangeError,
+    message: 'Maximum call stack size exceeded'
+  }
+);