Default uBO in addition to certain Firefox settings has the potential to crash not only the web browser but the entire Operating System

[PxCommoner]

Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
• This is not a support issue or a question. For support, questions, or help, visit /r/uBlockOrigin.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• uBO uses default lists and settings.
• using a new, unmodified browser profile.

Description

https://www.reddit.com/r/uBlockOrigin/comments/1h0f3wg/ublockorigin_can_cause_the_black_screen_of_death/

A specific URL where the issue occurs.

https://www.wealthfront.com/

Possibly more websites

Steps to Reproduce

1. Create a new Firefox Profile
2. Create prefs.js in the new profile with the contents: https://hastebin.skyra.pw/eyazuwagun.less
3. Launch Firefox using the new profile and download uBO from https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/
4. Visit https://www.wealthfront.com/ to turn Firefox into Google Chrome while acknowledging the following terms:
   - You will not hold me responsible for any lost work or damages for your system entering a black screen or irrecoverable state.
   - Closing the offending tab might not be enough to save your session. I have "successfully" crashed my system 3 more times trying to write this post while losing even more work.
   - Closing the tab may or may not prevent excessive consumption. On my system, I estimate that the rate of memory consumption to be from 3 - 5 GB / second. The memory consumption will continue for a few moments even after the tab is closed.
   - A rebound / refractory period may occur after 1 or 2 minutes in which excessive memory consumption will occur again and not stop until the system hangs, crashes, or enter a lobotomized state with many serious malfunctions requiring a complete system restart.

Expected behavior

My system not crashing in 5 minutes when I visit the webpage. At the very least, the tab should automatically crash or kill itself.

Actual behavior

My system does one of the following:

1. Briefly consume up to 100 GB of RAM in less than a minute just for visiting the website if timely intervention is taken.
2. Briefly consume up to 100 GB of RAM just for visiting the website if timely intervention is taken. After 1 - 2 minutes, RAM will begin to be consumed at a rapid rate until there is none left and the OS will either crash or enter a lobotomized state.
3. Consume all RAM and crash.

uBO version

1.61.2

Browser name and version

Firefox 132.0.2

Operating System and version

Windows 11 Pro 23H2

[uBlock-user]

uBO is JS/CSS/HTML, it cannot crash browser/operating system. Report crashes to browser vendors.

https://github.com/gorhill/uBlock/wiki/Can-uBO-crash-a-browser%3F

[stephenhawk8054]

At the very least, the tab should automatically crash or kill itself.

This should be handled by the browsers.

[gorhill]

I can't reproduce with default settings and default browser settings.

From the Reddit thread you posted, it appears the site is firing a firehose of navigator.sendBeacon() requests, and in such case this can lead to Firefox not garbage-collecting its memory fast enough, there was an issue on Bugzilla about this.

Create prefs.js in the new profile with the contents: https://hastebin.skyra.pw/eyazuwagun.less

You will have to figure out what in there is causing your issue. In your Reddit post you say "I don't know squat about computers", and in such case I advise you don't heavily modify browser default settings.

[gorhill]

I created a new profile with https://hastebin.skyra.pw/eyazuwagun.less, installed uBO 1.61.2, and still cannot reproduce your reported issue.

[gorhill]

@gwarser Found the specific config which triggers the issue:

user_pref("beacon.enabled", false);

I could reproduce this way (somehow the prefs.js file didn't work.)

From the dev network tab, I could see huge amount of network requests being fired, so this is the same sort of issue as the one that was filed in Bugzilla, which is that the garbage collection doesn't occur fast enough when a content blocker is installed and a site fires network requests in a loop non-stop.

This happens with any content blocker which blocks the network requests the site is trying to fire, not just uBO.

[PxCommoner]

this is the same sort of issue as the one that was filed in Bugzilla

Could you provide the link to the report? I don't see any reports that pertain to system crashing or garbage collection not being fast enough when looking up "beacon.enabled".

Would you also be able to explain why a combination of https://www.wealthfront.com/, default uBO, and

user_pref("beacon.enabled", false);

is able to have such disastrous consequences when visiting the website? I have visited many other websites without this issue ever occurring. If anything, I am surprised that I'm still able to use Youtube.com, which uBO regularly blocks >1k entities, without my system crashing.

[gorhill]

Could you provide the link to the report?

I can't find it, but I know it's in there somewhere in https://bugzilla.mozilla.org/query.cgi?format=specific. I think the issue was closed as won't fix.

It's essentially a site firing network requests non stop in a loop and at such a fast rate that the browser's garbage collector was not being fast enough to free up the transient memory consumed by the webRequest API when a content blocker is used.

Chromium was also affected but its garbage collector was able kicking in so it was less affected.

[PxCommoner]

Is the site firing so many network requests because of uBO? Can anything be done on uBO's end to prevent my scenario from ending up in an unusable state?

Shouldn't there be safeguards already implemented to prevent such an issue from occurring to begin with? I don't see why other anti-content blocker websites couldn't implement such tactics to eliminate the usage of content blockers.

[gorhill]

Is the site firing so many network requests because of uBO?

Not because of uBO specifically, as already pointed out, it happens with other content blockers. The site has a defect causing firehose of network requests, and Firefox's garbage collection does not kick in. That is the cause of the issue.

I don't see why other anti-content blocker websites couldn't implement such tactics to eliminate the usage of content blockers.

Yes, sites are free to sabotage themselves when you visit them. I am pretty sure this will eliminate visits to their site before it eliminate content blockers.

[uBlock-user]

I don't see why other anti-content blocker websites couldn't implement such tactics to eliminate the usage of content blockers.

Are you serious ? That's not how it works. I can add a filter to prevent the spam of network requests. All this spam creates is a horrible experience for visitors who will never visit that site again, the site will cease to exist, nothing will happen to content blockers.

[PxCommoner]

Not because of uBO specifically, as already pointed out, it happens with other content blockers.

And the network request spam only occurs when the content blocker is active? Imagine if many other websites were to adopt similar practices. Content blocker users would have to risk crashing their system when visiting a new website and have to add a filter for every website with such practices.

The "defect" causing the network request firehose ONLY occurs when I am using uBO. I do not see an excessive quantity of network requests when I visit the site without a content blocker and my current Firefox settings.

While my scenario also requires my Firefox config in order to crash when using uBO, I want to point out that based on what you have said, the meat of the issue is the fact that the website is spamming network requests because a content blocker is present (a blocked resource that is "essential" hence why the spam occurs?). What if other websites were to have "required" content that is blocked by content blockers? If such websites were to spam network requests until the content blocker lets the "required" content through, a fairly effective anti-content blocker measure has been implemented. Regular users will not be affected, whereas content blocker users will have to at the crash their system at least once to know that the website has an "defect" and make setting adjustments to continue to use their desired content blocker.

All this spam creates is a horrible experience for visitors who will never visit that site again

Yes, for visitors that use content blockers. If I go to https://www.wealthfront.com/ without uBO active or installed with my current Firefox profile, it loads completely fine and normal. I do not see anything malignant in the network pane of Developer Tools. The aforementioned website also does not provide intrusive or annoying ads and provides an investment service that many users may depend on. This is a website that I was expecting the lowest in probabilities in causing an issue from using uBO.