High CPU usage for 5+ minutes after visiting site with large (3.2 MB) Atom feed

[IcyDefiance]

Description

This bug currently happens on https://bevyengine.org/. After visiting their homepage, a Brave process maxes out a core of my CPU, as you can see in this screenshot from htop or this screenshot from Brave's task manager.

In addition, every time I navigate to a new page, another process starts maxing out another core of the CPU (screenshot), so just browsing around the site a bit will lock up the entire computer.

These processes continue to run for quite a while, even after closing the browser. The only way get rid of them is by killing the processes directly.

I'm confident the problem is caused by the atom feed, because the problem disappears if I build their site myself and comment out the following tag:

<link href="/atom.xml" rel="alternate" type="application/atom+xml" />

The problem also disappears if I change Zola (the framework they're using) to only put summaries in the feed, instead of the entire content of each page. I assume that's because it makes the feed file a lot smaller.

Steps to Reproduce

1. Visit https://bevyengine.org/
2. Open your process manager of choice to observe high CPU usage

Or, if they update their website to work around the issue:

1. Clone their website, checkout a commit from today, and serve it with Zola 0.16.1. Assuming bash on linux, these commands should work:

git clone https://github.com/bevyengine/bevy-website.git
cd bevy-website
git checkout 3143eac
docker run -u "$(id -u):$(id -g)" -v $PWD:/app --workdir /app -p 8080:8080 ghcr.io/getzola/zola:v0.16.1 serve --interface 0.0.0.0 --port 8080 --base-url localhost

2. Visit localhost:8080
3. Open your process manager of choice to observe high CPU usage

Actual result:

Screenshots in description above.

Expected result:

I can't figure out why Brave is even downloading the feed file. I'm just visiting the homepage of the website.

Reproduces how often:

Easily reproduced

Brave version (brave://version info)

Brave	1.49.120 Chromium: 111.0.5563.64 (Official Build) (64-bit)
Revision	c710e93d5b63b7095afe8c2c17df34408078439d-refs/branch-heads/5563@{#995}
OS	Linux

Also reproduced on Windows.

Version/Channel Information:

• Can you reproduce this issue with the current release? Yes
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? No
• Does the issue resolve itself when disabling Brave Rewards? No
• Is the issue reproducible on the latest version of Chrome? No

Miscellaneous Information: