child_process: validate arguments for null bytes

This change adds validation to reject an edge case where the
child_process API argument strings might contain null bytes
somewhere in between. Such strings were being silently truncated
before, so throwing an error should prevent misuses of this API.

Fixes: #44768
Signed-off-by: Darshan Sen <[email protected]>
PR-URL: #44782
Reviewed-By: James M Snell <[email protected]>

Author: RaisinTen

lib/child_process.js

@@ -39,6 +39,7 @@ const {
   ObjectPrototypeHasOwnProperty,
   RegExpPrototypeExec,
   SafeSet,
+  StringPrototypeIncludes,
   StringPrototypeSlice,
   StringPrototypeToUpperCase,
 } = primordials;
@@ -137,9 +138,11 @@ function fork(modulePath, args = [], options) {
   }
   options = { ...options, shell: false };
   options.execPath = options.execPath || process.execPath;
+  validateArgumentNullCheck(options.execPath, 'options.execPath');
 
   // Prepare arguments for fork:
   execArgv = options.execArgv || process.execArgv;
+  validateArgumentsNullCheck(execArgv, 'options.execArgv');
 
   if (execArgv === process.execArgv && process._eval != null) {
     const index = ArrayPrototypeLastIndexOf(execArgv, process._eval);
@@ -182,6 +185,9 @@ function _forkChild(fd, serializationMode) {
 }
 
 function normalizeExecArgs(command, options, callback) {
+  validateString(command, 'command');
+  validateArgumentNullCheck(command, 'command');
+
   if (typeof options === 'function') {
     callback = options;
     options = undefined;
@@ -286,6 +292,7 @@ function normalizeExecFileArgs(file, args, options, callback) {
   // Validate argv0, if present.
   if (options.argv0 != null) {
     validateString(options.argv0, 'options.argv0');
+    validateArgumentNullCheck(options.argv0, 'options.argv0');
   }
 
   return { file, args, options, callback };
@@ -536,6 +543,7 @@ function copyProcessEnvToEnv(env, name, optionEnv) {
 
 function normalizeSpawnArguments(file, args, options) {
   validateString(file, 'file');
+  validateArgumentNullCheck(file, 'file');
 
   if (file.length === 0)
     throw new ERR_INVALID_ARG_VALUE('file', file, 'cannot be empty');
@@ -551,6 +559,8 @@ function normalizeSpawnArguments(file, args, options) {
     args = [];
   }
 
+  validateArgumentsNullCheck(args, 'args');
+
   if (options === undefined)
     options = kEmptyObject;
   else
@@ -589,6 +599,7 @@ function normalizeSpawnArguments(file, args, options) {
   // Validate argv0, if present.
   if (options.argv0 != null) {
     validateString(options.argv0, 'options.argv0');
+    validateArgumentNullCheck(options.argv0, 'options.argv0');
   }
 
   // Validate windowsHide, if present.
@@ -604,6 +615,7 @@ function normalizeSpawnArguments(file, args, options) {
   }
 
   if (options.shell) {
+    validateArgumentNullCheck(options.shell, 'options.shell');
     const command = ArrayPrototypeJoin([file, ...args], ' ');
     // Set the shell, switches, and commands.
     if (process.platform === 'win32') {
@@ -681,6 +693,8 @@ function normalizeSpawnArguments(file, args, options) {
   for (const key of envKeys) {
     const value = env[key];
     if (value !== undefined) {
+      validateArgumentNullCheck(key, `options.env['${key}']`);
+      validateArgumentNullCheck(value, `options.env['${key}']`);
       ArrayPrototypePush(envPairs, `${key}=${value}`);
     }
   }
@@ -949,6 +963,20 @@ function execSync(command, options) {
 }
 
 
+function validateArgumentNullCheck(arg, propName) {
+  if (typeof arg === 'string' && StringPrototypeIncludes(arg, '\u0000')) {
+    throw new ERR_INVALID_ARG_VALUE(propName, arg, 'must be a string without null bytes');
+  }
+}
+
+
+function validateArgumentsNullCheck(args, propName) {
+  for (let i = 0; i < args.length; ++i) {
+    validateArgumentNullCheck(args[i], `${propName}[${i}]`);
+  }
+}
+
+
 function validateTimeout(timeout) {
   if (timeout != null && !(NumberIsInteger(timeout) && timeout >= 0)) {
     throw new ERR_OUT_OF_RANGE('timeout', 'an unsigned integer', timeout);

test/parallel/test-child-process-reject-null-bytes.js

@@ -0,0 +1,294 @@
+'use strict';
+const { mustNotCall } = require('../common');
+
+// Regression test for https://github.com/nodejs/node/issues/44768
+
+const { throws } = require('assert');
+const {
+  exec,
+  execFile,
+  execFileSync,
+  execSync,
+  fork,
+  spawn,
+  spawnSync,
+} = require('child_process');
+
+// Tests for the 'command' argument
+
+throws(() => exec(`${process.execPath} ${__filename} AAA BBB\0XXX CCC`, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'command' must be a string without null bytes/
+});
+
+throws(() => exec('BBB\0XXX AAA CCC', mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'command' must be a string without null bytes/
+});
+
+throws(() => execSync(`${process.execPath} ${__filename} AAA BBB\0XXX CCC`), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'command' must be a string without null bytes/
+});
+
+throws(() => execSync('BBB\0XXX AAA CCC'), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'command' must be a string without null bytes/
+});
+
+// Tests for the 'file' argument
+
+throws(() => spawn('BBB\0XXX'), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'file' must be a string without null bytes/
+});
+
+throws(() => execFile('BBB\0XXX', mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'file' must be a string without null bytes/
+});
+
+throws(() => execFileSync('BBB\0XXX'), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'file' must be a string without null bytes/
+});
+
+throws(() => spawn('BBB\0XXX'), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'file' must be a string without null bytes/
+});
+
+throws(() => spawnSync('BBB\0XXX'), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'file' must be a string without null bytes/
+});
+
+// Tests for the 'modulePath' argument
+
+throws(() => fork('BBB\0XXX'), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'modulePath' must be a string or Uint8Array without null bytes/
+});
+
+// Tests for the 'args' argument
+
+// Not testing exec() and execSync() because these accept 'args' as a part of
+// 'command' as space-separated arguments.
+
+throws(() => execFile(process.execPath, [__filename, 'AAA', 'BBB\0XXX', 'CCC'], mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'args\[2\]' must be a string without null bytes/
+});
+
+throws(() => execFileSync(process.execPath, [__filename, 'AAA', 'BBB\0XXX', 'CCC']), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'args\[2\]' must be a string without null bytes/
+});
+
+throws(() => fork(__filename, ['AAA', 'BBB\0XXX', 'CCC']), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'args\[2\]' must be a string without null bytes/
+});
+
+throws(() => spawn(process.execPath, [__filename, 'AAA', 'BBB\0XXX', 'CCC']), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'args\[2\]' must be a string without null bytes/
+});
+
+throws(() => spawnSync(process.execPath, [__filename, 'AAA', 'BBB\0XXX', 'CCC']), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The argument 'args\[2\]' must be a string without null bytes/
+});
+
+// Tests for the 'options.cwd' argument
+
+throws(() => exec(process.execPath, { cwd: 'BBB\0XXX' }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.cwd' must be a string or Uint8Array without null bytes/
+});
+
+throws(() => execFile(process.execPath, { cwd: 'BBB\0XXX' }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.cwd' must be a string or Uint8Array without null bytes/
+});
+
+throws(() => execFileSync(process.execPath, { cwd: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.cwd' must be a string or Uint8Array without null bytes/
+});
+
+throws(() => execSync(process.execPath, { cwd: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.cwd' must be a string or Uint8Array without null bytes/
+});
+
+throws(() => fork(__filename, { cwd: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.cwd' must be a string or Uint8Array without null bytes/
+});
+
+throws(() => spawn(process.execPath, { cwd: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.cwd' must be a string or Uint8Array without null bytes/
+});
+
+throws(() => spawnSync(process.execPath, { cwd: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.cwd' must be a string or Uint8Array without null bytes/
+});
+
+// Tests for the 'options.argv0' argument
+
+throws(() => exec(process.execPath, { argv0: 'BBB\0XXX' }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.argv0' must be a string without null bytes/
+});
+
+throws(() => execFile(process.execPath, { argv0: 'BBB\0XXX' }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.argv0' must be a string without null bytes/
+});
+
+throws(() => execFileSync(process.execPath, { argv0: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.argv0' must be a string without null bytes/
+});
+
+throws(() => execSync(process.execPath, { argv0: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.argv0' must be a string without null bytes/
+});
+
+throws(() => fork(__filename, { argv0: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.argv0' must be a string without null bytes/
+});
+
+throws(() => spawn(process.execPath, { argv0: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.argv0' must be a string without null bytes/
+});
+
+throws(() => spawnSync(process.execPath, { argv0: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.argv0' must be a string without null bytes/
+});
+
+// Tests for the 'options.shell' argument
+
+throws(() => exec(process.execPath, { shell: 'BBB\0XXX' }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.shell' must be a string without null bytes/
+});
+
+throws(() => execFile(process.execPath, { shell: 'BBB\0XXX' }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.shell' must be a string without null bytes/
+});
+
+throws(() => execFileSync(process.execPath, { shell: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.shell' must be a string without null bytes/
+});
+
+throws(() => execSync(process.execPath, { shell: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.shell' must be a string without null bytes/
+});
+
+// Not testing fork() because it doesn't accept the shell option (internally it
+// explicitly sets shell to false).
+
+throws(() => spawn(process.execPath, { shell: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.shell' must be a string without null bytes/
+});
+
+throws(() => spawnSync(process.execPath, { shell: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.shell' must be a string without null bytes/
+});
+
+// Tests for the 'options.env' argument
+
+throws(() => exec(process.execPath, { env: { 'AAA': 'BBB\0XXX' } }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['AAA'\]' must be a string without null bytes/
+});
+
+throws(() => exec(process.execPath, { env: { 'BBB\0XXX': 'AAA' } }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['BBB\0XXX'\]' must be a string without null bytes/
+});
+
+throws(() => execFile(process.execPath, { env: { 'AAA': 'BBB\0XXX' } }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['AAA'\]' must be a string without null bytes/
+});
+
+throws(() => execFile(process.execPath, { env: { 'BBB\0XXX': 'AAA' } }, mustNotCall()), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['BBB\0XXX'\]' must be a string without null bytes/
+});
+
+throws(() => execFileSync(process.execPath, { env: { 'AAA': 'BBB\0XXX' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['AAA'\]' must be a string without null bytes/
+});
+
+throws(() => execFileSync(process.execPath, { env: { 'BBB\0XXX': 'AAA' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['BBB\0XXX'\]' must be a string without null bytes/
+});
+
+throws(() => execSync(process.execPath, { env: { 'AAA': 'BBB\0XXX' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['AAA'\]' must be a string without null bytes/
+});
+
+throws(() => execSync(process.execPath, { env: { 'BBB\0XXX': 'AAA' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['BBB\0XXX'\]' must be a string without null bytes/
+});
+
+throws(() => fork(__filename, { env: { 'AAA': 'BBB\0XXX' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['AAA'\]' must be a string without null bytes/
+});
+
+throws(() => fork(__filename, { env: { 'BBB\0XXX': 'AAA' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['BBB\0XXX'\]' must be a string without null bytes/
+});
+
+throws(() => spawn(process.execPath, { env: { 'AAA': 'BBB\0XXX' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['AAA'\]' must be a string without null bytes/
+});
+
+throws(() => spawn(process.execPath, { env: { 'BBB\0XXX': 'AAA' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['BBB\0XXX'\]' must be a string without null bytes/
+});
+
+throws(() => spawnSync(process.execPath, { env: { 'AAA': 'BBB\0XXX' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['AAA'\]' must be a string without null bytes/
+});
+
+throws(() => spawnSync(process.execPath, { env: { 'BBB\0XXX': 'AAA' } }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.env\['BBB\0XXX'\]' must be a string without null bytes/
+});
+
+// Tests for the 'options.execPath' argument
+throws(() => fork(__filename, { execPath: 'BBB\0XXX' }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.execPath' must be a string without null bytes/
+});
+
+// Tests for the 'options.execArgv' argument
+throws(() => fork(__filename, { execArgv: ['AAA', 'BBB\0XXX', 'CCC'] }), {
+  code: 'ERR_INVALID_ARG_VALUE',
+  message: /The property 'options\.execArgv\[1\]' must be a string without null bytes/
+});