segfault when using ESM dynamic import repeatedly in special circumstances

[mkg20001]

Version

v16.8.0

Platform

Linux mkg-razer 5.10.61 #1-NixOS SMP Thu Aug 26 12:51:21 UTC 2021 x86_64 GNU/Linux

Subsystem

ESM modules

What steps will reproduce the bug?

• Create a package.json with at least "type": "module" set
• Create a file b.js with the following contents

export default () => {}

• Open a nodeJS repl and paste the following

async function require (thing) {
  const imported = await import(thing) // "dynamic import"
  return Object.assign(imported.default, imported)
}

require('./b.js')

Wait a few seconds and run require('./b.js') again

How often does it reproduce? Is there a required condition?

Sometimes it doesn't segfault, try running require('./b.js') again a few times, or try something like require('./b.js').then(console.log)

What is the expected behavior?

It should return the module

What do you see instead?

It segfaults

Segmentation fault (Speicherabzug geschrieben)

Additional information

No response

[devsnek]

Duplicate of #35889

[bnoordhuis]

Reopening because of #35889 (comment). I can reproduce the segfault with v19.x but it may not be the exact same bug as #35889 because it only happens in the REPL and doesn't use importModuleDynamically.

FWIW, it does not reproduce with the test case below:

// echo '{"type":"module"}' > package.json
import fs from 'node:fs'
let i = 0
async function go() {
  const filename = `./m${i++}.js`
  fs.writeFileSync(filename, 'export default() => {}')
  const m = await import(filename)
  Object.assign(m.default, m)
  setTimeout(go, 250)
}
go()

[mkg20001]

The bug reproduces only after a few tries sometimes, so maybe 1) it would need to be ran as setInterval or 2) it would need to be ran after the module has loaded (as the bug may be related to the module being loaded again or something like it)

Edit: Tried interval with my original repro but that didn't work when ran via node test.js. It works reliably on REPL with both interval and timeout, so it requires the module to be already loaded to cause the issue.

async function require (thing) {
  const imported = await import(thing) // "dynamic import"
  return Object.assign(imported.default, imported)
}

require('./b.js')

setTimeout(() => require('./b.js'), 1000)