2078456 - Firefox 157 ghost windows on github.com: inner windows are held by unknown native references after navigation

Status: RESOLVED DUPLICATE of bug 2079806

(Core :: Networking: Cookies, defect)

Description

[Christian Blais]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:157.0) Gecko/20100101 Firefox/157.0

Steps to reproduce

Open https://github.com/pulls/authored. Click a PR, then click another PR in the same tab. Do this a few times. Open about:memory → Minimize memory usage → Measure.

Actual results

Every PR or list page you navigated away from stays as a ghost window: 14 ghosts, 588 MB in one content process after about an hour. CPU usage goes up as well. find_roots.py on a verbose CC log reports each ghost nsGlobalWindowInner as a root with unknown edges (2 to 116 per window). The windows survive Minimize memory usage.

Expected results

Windows are freed after bfcache eviction.

Comment 1

[hashcatHitman[:hashcatHitman]]

Do you have any add-ons installed in your profile?

If yes, could you post the list (you can find a table at about:support#addons)? Ghost windows are typically associated with add-ons, so that list will probably be desired.

Possibly related/duplicate: https://bugzilla.mozilla.org/show_bug.cgi?id=1949248

Comment 2

[Manuel Bucher [:manuel]]

I think this is likely bug 2079806.

Comment 3

[BugBot [:suhaib / :marco]]

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Cocoa' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 4

[Stephen A Pohl [:spohl]]

Moving this to the same component as bug 2079806.

Comment 5

[Jost Schulte]

Same issue here on Firefox 157.0.1, macOS 26.5. Only extension installed is uBlock Origin 1.75.0. Anonymized about:memory report attached.

• The github.com content process reached 1.58 GB explicit. 850 MB of that is held by 26 ghost windows, plus 127 MB of orphan DOM nodes.
• Two other content processes have 6 ghost windows each (220 MB and 161 MB).
• The tabs freeze for several seconds once the process gets to around 1 GB.
• The same browsing in Brave doesn't show this.

Comment 6

[Jost Schulte]

Attachment: Memory report when tabs starting to freeze

Comment 7

[Manuel Bucher [:manuel]]

@reporter: Thanks for the report btw. Could you please check whether this is still a problem on Fx 159 released yesterday? It includes the fix for bug 2079806 and might have solved the problem.

Comment 8

[Jost Schulte]

The ghost window problem is indeed not happening anymore. The Github pages' memory isn't growing indefinitely. However, the mattermost page is still growing immensely, but that must be a different issue. I'll open a new bug.

Comment 9

[Manuel Bucher [:manuel]]

Thanks for the bug report and also @jost for confirming that this isn't happening anymore. I'm going to close as duplicate of bug 2079806 due to describing the same problem and containing the fix. Feel welcome to open new bugs for other problems you observe (thanks for filing the mastodon bug separately).