1995937 - Browser/NTP hangs when a specific string is entered in web console or browser console

Status: NEW

(DevTools :: Console, enhancement, P3)

Description

[Catalin Sasca, Desktop Test Engineering [:csasca]]

Found in

• Firefox 145.0b5

Affected versions

• Firefox 145.0b5
• Firefox 146.0a1

Tested platforms

• Affected platforms: Windows 11, Ubuntu 24.04, macOS 26.0.1

Steps to reproduce

1. Access browser console
2. Input "while(true);" and press enter
3. Interact with New Tab page

Expected result

• The New tab page does not hang

Actual result

• The new tab page hangs and cannot be used until Firefox is restarted

Regression range

• Will see for a regression

Additional notes

• The issue can be seen in the following attachment
• If the same steps are followed but web console is used instead, the whole browser will hang (see attachment above)

Comment 1

[Julian Descottes [:jdescottes]]

We most likely already have bugs filed to make the webconsole safe to execute incorrect scripts, but I couldn't find duplicates at the moment.

I don't think this is a regression, but if you happen to find a regression window, let us know.

Comment 2

[Julian Descottes [:jdescottes]]

If you try to interact with the content page after running the infinite loop, it should allow to trigger the slow script detector and should allow you to stop the script.

Comment 3

[Alexandre Poirot [:ochameau]]

May be a duplicate of bug 1903728. Bug 1884377 is also having more context and some other interesting "see also" bugs.

Comment 4

[Catalin Sasca, Desktop Test Engineering [:csasca]]

Yep, tried looking for a regression but the behavior is the same even on older builds as Firefox 58.0a1 (2017-10-26).