From f304f915b251216c8d6d26a94e6508a3101a2ac8 Mon Sep 17 00:00:00 2001
From: Xavier Stouder <xavier@stouder.io>
Date: Sat, 13 Dec 2025 02:10:45 +0100
Subject: [PATCH 1/4] os: freeze signals constant

Remove the ability to mutate signals constant as doing so can lead to
unexpected behavior, notably when spawning child process.

Fixes: https://github.com/nodejs/node/issues/44749
---
 lib/os.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/os.js b/lib/os.js
index 9f062fea04d9ea..6305c701243e78 100644
--- a/lib/os.js
+++ b/lib/os.js
@@ -27,6 +27,7 @@ const {
   ObjectDefineProperties,
   StringPrototypeSlice,
   SymbolToPrimitive,
+  ObjectFreeze,
 } = primordials;
 
 const { getTempDir } = internalBinding('credentials');
@@ -330,6 +331,8 @@ module.exports = {
   machine: getMachine,
 };
 
+ObjectFreeze(constants.signals);
+
 ObjectDefineProperties(module.exports, {
   constants: {
     __proto__: null,

From c66f71d92de50b3f61c2f8da29c9fe69ea8df3fc Mon Sep 17 00:00:00 2001
From: Xavier Stouder <xavier@stouder.io>
Date: Sat, 13 Dec 2025 02:25:22 +0100
Subject: [PATCH 2/4] os: add test for signals constant immutability

---
 test/parallel/test-os-constants-signals.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 test/parallel/test-os-constants-signals.js

diff --git a/test/parallel/test-os-constants-signals.js b/test/parallel/test-os-constants-signals.js
new file mode 100644
index 00000000000000..0efc413ca28584
--- /dev/null
+++ b/test/parallel/test-os-constants-signals.js
@@ -0,0 +1,12 @@
+'use strict';
+
+const common = require('../common');
+const { test } = require('node:test');
+const assert = require('node:assert');
+const { constants } = require('node:os');
+
+const { internalBinding } = require('internal/test/binding');
+
+test('Verify that signals constant is immutable', () => {
+    assert.throws(() => constants.signals.FOOBAR = 1337, TypeError);
+})
\ No newline at end of file

From 4b1a36ca7992fcce371b42662c80d09419536249 Mon Sep 17 00:00:00 2001
From: Xavier Stouder <xavier@stouder.io>
Date: Sat, 13 Dec 2025 02:35:07 +0100
Subject: [PATCH 3/4] os: run linter on test too

---
 test/parallel/test-os-constants-signals.js | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/test/parallel/test-os-constants-signals.js b/test/parallel/test-os-constants-signals.js
index 0efc413ca28584..5e6daf19019392 100644
--- a/test/parallel/test-os-constants-signals.js
+++ b/test/parallel/test-os-constants-signals.js
@@ -1,12 +1,10 @@
 'use strict';
 
-const common = require('../common');
 const { test } = require('node:test');
 const assert = require('node:assert');
 const { constants } = require('node:os');
 
-const { internalBinding } = require('internal/test/binding');
 
 test('Verify that signals constant is immutable', () => {
-    assert.throws(() => constants.signals.FOOBAR = 1337, TypeError);
-})
\ No newline at end of file
+  assert.throws(() => constants.signals.FOOBAR = 1337, TypeError);
+});

From 55ff2a1b72cad6a00449ab59517a1be6ca488478 Mon Sep 17 00:00:00 2001
From: Xavier Stouder <xavier@stouder.io>
Date: Sat, 13 Dec 2025 02:42:30 +0100
Subject: [PATCH 4/4] fix ci

---
 lib/os.js                                  | 2 +-
 test/parallel/test-os-constants-signals.js | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/os.js b/lib/os.js
index 6305c701243e78..5e53879bd6d5aa 100644
--- a/lib/os.js
+++ b/lib/os.js
@@ -25,9 +25,9 @@ const {
   ArrayPrototypePush,
   Float64Array,
   ObjectDefineProperties,
+  ObjectFreeze,
   StringPrototypeSlice,
   SymbolToPrimitive,
-  ObjectFreeze,
 } = primordials;
 
 const { getTempDir } = internalBinding('credentials');
diff --git a/test/parallel/test-os-constants-signals.js b/test/parallel/test-os-constants-signals.js
index 5e6daf19019392..a4fac1b63566fa 100644
--- a/test/parallel/test-os-constants-signals.js
+++ b/test/parallel/test-os-constants-signals.js
@@ -1,5 +1,6 @@
 'use strict';
 
+require('../common');
 const { test } = require('node:test');
 const assert = require('node:assert');
 const { constants } = require('node:os');