Add per-tab memory limits to prevent system freeze (possible DoS behavior)

[ripperanti]

Hi Firefox team,

I wanted to report an issue I ran into recently that might point to a potential vulnerability or at least a stability concern.

While browsing a certain video streaming website (not official, but not malicious either), a single tab in Firefox suddenly started consuming a massive amount of RAM — to the point where my system's memory usage reached 100%. I checked Firefox’s internal Task Manager, and that one tab alone was using several gigabytes of memory, far more than any other.

Shortly after, my system slowed down dramatically, and the GPU driver crashed and restarted. Eventually, Firefox and the OS recovered, but the system became nearly unusable for a while. It seemed like the tab triggered some sort of memory allocation loop, possibly using WebGL or an intensive video renderer.

There was no warning, crash, or limit applied — Firefox just allowed the tab to keep growing in memory until the system reached critical levels. It felt like an unintentional denial-of-service (DoS) triggered just by visiting a page with heavy multimedia content.

### Suggestion:
It would be great if Firefox had some kind of <<per-tab memory usage cap>> or at least monitoring that could:
- Warn the user when a tab starts using excessive memory,
- Or automatically suspend/terminate the tab if it goes beyond a safe threshold.

This could help prevent one misbehaving page from affecting the entire system, especially in systems with shared GPU/RAM setups.

Thanks for all the work you do — Firefox is my daily browser and I love it. Just wanted to share this in hopes it helps make it even more robust.

Best regards, JASTO

[Jon]

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