domain: use strong reference to domain while active

When an uncaught exception is thrown inside a domain, the domain is
removed from the stack as of 43a51708589ac789ce08beaeb49d6d778dfbdc49.
This means that it might not be kept alive as an object anymore,
and may be garbage collected before the `after()` hook can run,
which tries to exit it as well.

Resolve that by making references to the domain strong while it is
active.

Fixes: https://github.com/nodejs/node/issues/28275

PR-URL: https://github.com/nodejs/node/pull/28313
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Vladimir de Turckheim <vlad2t@hotmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/lib/domain.js b/lib/domain.js
index b2ffed2741..3dc56c179a 100644
--- a/lib/domain.js
+++ b/lib/domain.js
@@ -73,13 +73,18 @@ const asyncHook = createHook({
     if (current !== undefined) { // Enter domain for this cb
       // We will get the domain through current.get(), because the resource
       // object's .domain property makes sure it is not garbage collected.
+      // However, we do need to make the reference to the domain non-weak,
+      // so that it cannot be garbage collected before the after() hook.
+      current.incRef();
       current.get().enter();
     }
   },
   after(asyncId) {
     const current = pairing.get(asyncId);
     if (current !== undefined) { // Exit domain for this cb
-      current.get().exit();
+      const domain = current.get();
+      current.decRef();
+      domain.exit();
     }
   },
   destroy(asyncId) {