Found in

• Firefox 110.0a1 (Build Id: 20230102165835)

Affected versions

• Firefox 110.0a1 (Build Id: 20230102165835)

Tested platforms

• Affected platforms: Windows 10 64bit

Preconditions

1. Have Google Drive for desktop installed (https://www.google.com/drive/download/)
2. Launch Firefox.
3. Block the drivefsext.dll via the about:third-party page.
4. Restart Firefox.

Steps to reproduce

1. Disable the user-driven DLL blocking by using the following policy inside the policies.json file:
   { "policies": { "DisableThirdPartyModuleBlocking": true } }
2. Restart Firefox.
3. Press ALT + F and select "Open File".
4. Access the about:third-party page and inspect the drivefsext.dll.

Expected result

• Step 3: The Google Drive entries have a little cloud overlay displayed.
• Step 4: The drivefsext.dll has the status of Loaded.

Actual result

• Step 3: No cloud overlay is displayed for the Google Drive entries.
• Step 4: The drivefsext.dll has the status of Blocked.

Regression range

• This is not a regression.

The problem is that InitializeDllBlocklistOOPFromLauncher() calls PolicyCheckBoolean(L"DisableThirdPartyModuleBlocking") to see if the blocklist is disabled, but that just checks the registry key. (the about:third-party page itself does seem to work correctly) I'm not sure if we should be reading the JSON file to look for this specifically...

So this is going to be a limitation.

You can only turn off the blocklist via GPO, not policies.json. This is similar to a few other Windows specific policies.

Sorry, I should have caught that when this report was opened.

Thanks for the info! I was not aware of that :D.

I'm going to update our tests & will apply this policy directly via regedit or GPO instead.

My guess is that we can mark this ticket as wontfix then?

Thanks for the info! I was not aware of that :D.

I should have caught that.

My guess is that we can mark this ticket as wontfix then?

yep