fs: validate encoding to binding.writeString()

The binding layer performs some validation of the encoding and
data passed to WriteString(). This commit adds similar validation
to the JS layer for better error handling.

PR-URL: https://github.com/nodejs/node/pull/38183
Fixes: https://github.com/nodejs/node/issues/38168
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>

2 files changed, 8 insertions, 1 deletions

diff --git a/lib/fs.js b/lib/fs.js
index 6bf068416f..937b45cdb5 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -133,6 +133,7 @@ const {
   validateBoolean,
   validateBuffer,
   validateCallback,
+  validateEncoding,
   validateFunction,
   validateInteger,
 } = require('internal/validators');
@@ -702,11 +703,14 @@ function write(fd, buffer, offset, length, position, callback) {
     }
     length = 'utf8';
   }
+
+  const str = String(buffer);
+  validateEncoding(str, length);
   callback = maybeCallback(position);
 
   const req = new FSReqCallback();
   req.oncomplete = wrapper;
-  return binding.writeString(fd, String(buffer), offset, length, req);
+  return binding.writeString(fd, str, offset, length, req);
 }
 
 ObjectDefineProperty(write, internalUtil.customPromisifyArgs,
@@ -735,6 +739,7 @@ function writeSync(fd, buffer, offset, length, position) {
                                  undefined, ctx);
   } else {
     validateStringAfterArrayBufferView(buffer, 'buffer');
+    validateEncoding(buffer, length);
 
     if (offset === undefined)
       offset = null;
diff --git a/lib/internal/fs/promises.js b/lib/internal/fs/promises.js
index 791bf57a7d..683969e2ec 100644
--- a/lib/internal/fs/promises.js
+++ b/lib/internal/fs/promises.js
@@ -70,6 +70,7 @@ const {
   validateAbortSignal,
   validateBoolean,
   validateBuffer,
+  validateEncoding,
   validateInteger,
 } = require('internal/validators');
 const pathModule = require('path');
@@ -467,6 +468,7 @@ async function write(handle, buffer, offset, length, position) {
   }
 
   validateStringAfterArrayBufferView(buffer, 'buffer');
+  validateEncoding(buffer, length);
   const bytesWritten = (await binding.writeString(handle.fd, buffer, offset,
                                                   length, kUsePromises)) || 0;
   return { bytesWritten, buffer };