--experimental-permission breaks REPL

[tniessen]

Version

20.5.0

Platform

any

Subsystem

permission model

What steps will reproduce the bug?

Open a REPL and start typing:

$ node --experimental-permission --allow-fs-read=/
> f

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

Always.

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

No error.

What do you see instead?

Fatal error:

node:internal/readline/emitKeypressEvents:74
            throw err;
            ^

Error: Access to this API has been restricted
    at Session.connect (node:inspector:68:7)
    at sendInspectorCommand (node:internal/util/inspector:52:11)
    at getGlobalLexicalScopeNames (node:repl:1262:10)
    at REPLServer.complete (node:repl:1493:26)
    at REPLServer.completer (node:repl:783:5)
    at showCompletionPreview (node:internal/repl/utils:230:10)
    at showPreview (node:internal/repl/utils:384:7)
    at REPLServer.self._ttyWrite (node:repl:1020:9)
    at ReadStream.onkeypress (node:internal/readline/interface:264:20)
    at ReadStream.emit (node:events:514:28) {
  code: 'ERR_ACCESS_DENIED',
  permission: 'Inspector',
  resource: 'Connect'
}

Node.js v20.5.0

Additional information

Likely side effect of 34d92ed.

[RafaelGSS]

Hi, thanks for reporting it. I'm aware of this behaviour.

[targos]

Question is: should we make the internal calls to the inspector possible/privileged, or do like when the inspector is unavailable (this would just be a new condition in

node/lib/internal/util/inspector.js

Lines 48 to 49 in a0f3ed8

	const { hasInspector } = internalBinding('config');
	if (!hasInspector) return onError();

)

[RafaelGSS]

I believe REPL shouldn't be available when the permission model is enabled. Please let me know if I'm wrong, but the REPL can create a new V8 isolate and bypass any permission in several ways. If we start supporting REPL, it would mean that we need to cover all those cases.

[targos]

the REPL can create a new V8 isolate and bypass any permission in several ways

Can you elaborate?

[RafaelGSS]

the REPL can create a new V8 isolate and bypass any permission in several ways

Can you elaborate?

Basically, the same as 34d92ed fixes. I don't have a reproducible example because I'm not sure if that's possible. I'm just wondering if REPL can create a new V8 isolate, it means it could create without the experimental permission rules, right?

Anyway, I created the #48920.