From 4f28da883fbdabb886b0e8817596ec66d9e66381 Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Sun, 16 Dec 2018 14:34:37 +0100
Subject: [PATCH] worker: fix nullptr deref after MessagePort deser failure

This would previously always have crashed when deserializing
a `MessagePort` fails, because there was always at least one
`nullptr` entry in the vector.

PR-URL: https://github.com/nodejs/node/pull/25076
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
---
 src/node_messaging.cc                          |  3 ++-
 ...st-worker-messageport-transfer-terminate.js | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 test/parallel/test-worker-messageport-transfer-terminate.js

diff --git a/src/node_messaging.cc b/src/node_messaging.cc
index c9b5e324479975..ae60187b6f3ec2 100644
--- a/src/node_messaging.cc
+++ b/src/node_messaging.cc
@@ -90,7 +90,8 @@ MaybeLocal<Value> Message::Deserialize(Environment* env,
     if (ports[i] == nullptr) {
       for (MessagePort* port : ports) {
         // This will eventually release the MessagePort object itself.
-        port->Close();
+        if (port != nullptr)
+          port->Close();
       }
       return MaybeLocal<Value>();
     }
diff --git a/test/parallel/test-worker-messageport-transfer-terminate.js b/test/parallel/test-worker-messageport-transfer-terminate.js
new file mode 100644
index 00000000000000..13a30b5c54c6c3
--- /dev/null
+++ b/test/parallel/test-worker-messageport-transfer-terminate.js
@@ -0,0 +1,18 @@
+// Flags: --experimental-worker
+'use strict';
+require('../common');
+const { Worker, MessageChannel } = require('worker_threads');
+
+// Check the interaction of calling .terminate() while transferring
+// MessagePort objects; in particular, that it does not crash the process.
+
+for (let i = 0; i < 10; ++i) {
+  const w = new Worker(
+    "require('worker_threads').parentPort.on('message', () => {})",
+    { eval: true });
+  setImmediate(() => {
+    const port = new MessageChannel().port1;
+    w.postMessage({ port }, [ port ]);
+    w.terminate();
+  });
+}