nodejs / nodejs/node

`ObjectWrap` cleanup hooks break pre-built addons on Node.js 26.0.0-26.3.1 runtimes

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addons c++
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Description

Version

Node.js headers 26.4.0 or newer
Node.js runtime 26.0.0 up to and including 26.3.1

Platform
Not platform specific, but used:
Linux 7.0.0-28-generic #28~24.04.1-Ubuntu x86_64 x86_64 x86_64 GNU/Linux
Subsystem

src, addons

What steps will reproduce the bug?

The crash depends on header and runtime version. So you will need headers from e.g. Node.js 26.4.0 and two runtimes (e.g. 26.2.0 and 26.4.0)

  1. Sample that just uses ObjectWrap
    addon.cc:
#include <node.h>
#include <node_object_wrap.h>

using namespace v8;

class Thing : public node::ObjectWrap {
 public:
  static void New(const FunctionCallbackInfo<Value>& args) {
    (new Thing())->Wrap(args.This());
  }
};

void Init(Local<Object> exports) {
  Isolate* isolate = Isolate::GetCurrent();
  Local<Context> context = isolate->GetCurrentContext();
  Local<FunctionTemplate> tpl = FunctionTemplate::New(isolate, Thing::New);
  tpl->InstanceTemplate()->SetInternalFieldCount(1);
  exports->Set(context,
               String::NewFromUtf8(isolate, "Thing").ToLocalChecked(),
               tpl->GetFunction(context).ToLocalChecked()).Check();
}

NODE_MODULE(NODE_GYP_MODULE_NAME, Init)

index.js:

const { Thing } = require('./addon.node');

let junk = [];
for (let i = 0; i < 300000; i++) {
  new Thing();                          // wrapped object, immediately unreachable
  junk.push({ a: i });                  // keep allocation rate high so V8 collects on its own
  if (junk.length > 1000) junk = [];
}
console.log('survived');
  1. Compile against 26.4.0 (or newer if you want)
g++ -std=c++20 -fPIC -shared \
    -I</path/to/node-v26.4.0-linux-x64/include/node> \
    -DNODE_GYP_MODULE_NAME=addon \
    -o addon.node addon.cc
  1. Run same binary against two different Node.js versions
# this one will run fine
<path/to/node_26.4> index.js

# this one will crash
<path/to/node_26.2> index.js
How often does it reproduce? Is there a required condition?

Deterministically with 5/5 runs.
See this table for when it crashes:

hdr \ rt 26.0.0 26.3.1 26.4.0 26.7.0
26.0.0 ok ok ok ok
26.3.1 ok ok ok ok
26.4.0 crash crash ok ok
26.7.0 crash crash ok ok

I.e. it crashes with headers >= 26.4.0 when runtime <= 26.3.1.

A explicit trigger of the gc via global.gc() will not cause the failure, it has to be an allocation-driven one.

What is the expected behavior? Why is that the expected behavior?

A pre-built addon that is built against headers of one 26.x release should keep working on another 26.x runtime

What do you see instead?
  #  node[278507]: void node::RemoveEnvironmentCleanupHook(Isolate *, CleanupHook, void *) at ../src/api/hooks.cc:130
  #  Assertion failed: (env) != nullptr

----- Native stack trace -----

 1: 0x813228 node::Assert(node::AssertionInfo const&) [node]
 2: 0x891b90 node::RemoveEnvironmentCleanupHook(v8::Isolate*, void (*)(void*), void*) [node]
 3: 0x73f036ca4045 node::ObjectWrap::RemoveCleanupHook() [/home/user/reproducer/addon.node]
 4: 0x73f036ca393a node::ObjectWrap::~ObjectWrap() [/home/user/reproducer/addon.node]
 5: 0x73f036ca41ec Thing::~Thing() [/home/user/reproducer/addon.node]
 6: 0x73f036ca420c Thing::~Thing() [/home/user/reproducer/addon.node]
 7: 0x73f036ca3fdd node::ObjectWrap::WeakCallback(v8::WeakCallbackInfo<node::ObjectWrap> const&) [/home/user/reproducer/addon.node]
 8: 0xe18a09  [node]
 9: 0xeb3f61  [node]
10: 0xec4582  [node]
11: 0xec425f  [node]
12: 0x194cdf7  [node]
13: 0xeb0372  [node]
14: 0xea3914  [node]
15: 0xea373c  [node]
16: 0xea30cf  [node]
17: 0xe7f25d  [node]
18: 0x133d781  [node]
19: 0x73f02763ea76 
Aborted (core dumped)
Additional information

The causing code change in 26.4.0 is the RemoveCleanupHook(); line added to destructor in commit 7ac3fe1992e189502c9153adbd34a6e38643e208. The call interacts with the improvement of the RemoveEnvironmentCleanupHook function in 1723773d4133fc71215a9cbb7e2b9a2a11fc3688.

When the destructor is called due to headers being 26.4.0 or newer, but the runtime being <= 26.3.1, then it can trigger the CHECK_NOT_NULL(env); of the RemoveEnvironmentCleanupHook function.

Refs: #63642 #63985

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the ObjectWrap destructor and RemoveEnvironmentCleanupHook call described in src/api/hooks.cc:130, then reproduce using addon.cc and index.js with 26.4.0 headers against the two runtime versions. Compare the changes from commits 7ac3fe1992e189502c9153adbd34a6e38643e208 and 1723773d4133fc71215a9cbb7e2b9a2a11fc3688. Done means pre-built addons no longer abort on supported 26.x runtime combinations.

Written by the indexing model from the issue text.

Assessment

Tech stack
cpp, javascript, node.js
Domain
backend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
52/100

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