From bebc86d9af7d2a2f0ff7c1e8ce65a8aad4a53730 Mon Sep 17 00:00:00 2001
From: Archkon <180910180+Archkon@users.noreply.github.com>
Date: Thu, 6 Aug 2026 12:58:33 +0800
Subject: [PATCH] process: reject null bytes in chdir paths

Validate directory strings before calling the native chdir binding to
prevent paths from being truncated at embedded null bytes.

Signed-off-by: Archkon <180910180+Archkon@users.noreply.github.com>
---
 lib/internal/bootstrap/switches/does_own_process_state.js | 4 ++--
 test/parallel/test-process-chdir.js                       | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/internal/bootstrap/switches/does_own_process_state.js b/lib/internal/bootstrap/switches/does_own_process_state.js
index 370da66a825f..5019a8ff2ee3 100644
--- a/lib/internal/bootstrap/switches/does_own_process_state.js
+++ b/lib/internal/bootstrap/switches/does_own_process_state.js
@@ -32,7 +32,7 @@ if (credentials.implementsPosixCredentials) {
 const {
   parseFileMode,
   validateArray,
-  validateString,
+  validateStringWithoutNullBytes,
   validateUint32,
 } = require('internal/validators');
 
@@ -124,7 +124,7 @@ if (isBuildingSnapshot()) {
 }
 
 function wrappedChdir(directory) {
-  validateString(directory, 'directory');
+  validateStringWithoutNullBytes(directory, 'directory');
   rawMethods.chdir(directory);
   // Mark cache that it requires an update.
   cachedCwd = '';
diff --git a/test/parallel/test-process-chdir.js b/test/parallel/test-process-chdir.js
index 42d2a60c8ec6..ed11665998e4 100644
--- a/test/parallel/test-process-chdir.js
+++ b/test/parallel/test-process-chdir.js
@@ -44,3 +44,9 @@ const err = {
 };
 assert.throws(function() { process.chdir({}); }, err);
 assert.throws(function() { process.chdir(); }, err);
+
+assert.throws(() => process.chdir(`${dir}\u0000ignored`), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  name: 'TypeError',
+  message: /The argument 'directory' must be a string without null bytes/,
+});