From e8761186a5a55f6a69907fffc2684c68c83f0361 Mon Sep 17 00:00:00 2001
From: Zach Bjornson <zbbjornson@gmail.com>
Date: Tue, 4 May 2021 22:24:29 -0700
Subject: [PATCH] fs: fix error when writing buffers > INT32_MAX

This reverts c380ee6785b72fd2f24803de80bb412dfc32e8a9.
uv_fs_write returns an int, so it is not possible to ask
it to write more than INT32_MAX.

Instead, validate 'length' is an int32 in JS to avoid
the assertion failure.

PR-URL: https://github.com/nodejs/node/pull/38546
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
---
 lib/internal/fs/utils.js                    |  2 ++
 src/node_file.cc                            |  4 +--
 test/parallel/test-fs-write-buffer-large.js | 40 +++++++++++++++++++++
 3 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 test/parallel/test-fs-write-buffer-large.js

diff --git a/lib/internal/fs/utils.js b/lib/internal/fs/utils.js
index 3b7754292821f3..322b1519ef2807 100644
--- a/lib/internal/fs/utils.js
+++ b/lib/internal/fs/utils.js
@@ -659,6 +659,8 @@ const validateOffsetLengthWrite = hideStackFrames(
     if (length < 0) {
       throw new ERR_OUT_OF_RANGE('length', '>= 0', length);
     }
+
+    validateInt32(length, 'length', 0);
   }
 );
 
diff --git a/src/node_file.cc b/src/node_file.cc
index b8902f6b348eca..d3bcb8fbd804c7 100644
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -1835,8 +1835,8 @@ static void WriteBuffer(const FunctionCallbackInfo<Value>& args) {
   CHECK_LE(static_cast<uint64_t>(off_64), buffer_length);
   const size_t off = static_cast<size_t>(off_64);
 
-  CHECK(IsSafeJsInt(args[3]));
-  const size_t len = static_cast<size_t>(args[3].As<Integer>()->Value());
+  CHECK(args[3]->IsInt32());
+  const size_t len = static_cast<size_t>(args[3].As<Int32>()->Value());
   CHECK(Buffer::IsWithinBounds(off, len, buffer_length));
   CHECK_LE(len, buffer_length);
   CHECK_GE(off + len, off);
diff --git a/test/parallel/test-fs-write-buffer-large.js b/test/parallel/test-fs-write-buffer-large.js
new file mode 100644
index 00000000000000..a80072354eaa0f
--- /dev/null
+++ b/test/parallel/test-fs-write-buffer-large.js
@@ -0,0 +1,40 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const path = require('path');
+const fs = require('fs');
+
+const tmpdir = require('../common/tmpdir');
+tmpdir.refresh();
+
+// fs.write with length > INT32_MAX
+
+common.skipIf32Bits();
+
+let buf;
+try {
+  buf = Buffer.allocUnsafe(0x7FFFFFFF + 1);
+} catch (e) {
+  // If the exception is not due to memory confinement then rethrow it.
+  if (e.message !== 'Array buffer allocation failed') throw (e);
+  common.skip('skipped due to memory requirements');
+}
+
+const filename = path.join(tmpdir.path, 'write9.txt');
+fs.open(filename, 'w', 0o644, common.mustSucceed((fd) => {
+  assert.throws(() => {
+    fs.write(fd,
+             buf,
+             0,
+             0x7FFFFFFF + 1,
+             0,
+             common.mustNotCall());
+  }, {
+    code: 'ERR_OUT_OF_RANGE',
+    name: 'RangeError',
+    message: 'The value of "length" is out of range. ' +
+      'It must be >= 0 && <= 2147483647. Received 2147483648'
+  });
+
+  fs.closeSync(fd);
+}));