0002874: Extreme resource use allowed in JavaScript

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Date Submitted

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0002874

NetSurf

Javascript

public

2024-05-28 14:02

Reporter

Felix Albrigtsen

Assigned To

Severity

minor

Reproducibility

always

Status

new

Resolution

open

Platform

GTK

Linux

OS Version

Debian 13 Trixie

Product Version

3.11

Target Version

Fixed in Version

Summary

0002874: Extreme resource use allowed in JavaScript

Description

When NetSurf opens the HTML file shown below, it consumes 100% of a CPU core and at least 30 GB of memory, with no safeguards, meaning it will continue consuming memory until it is eventually done, or the system's OOM killer stops NetSurf or kills another process.

The root of this issue might be in the Duktape JavaScript engine itself, and be out of scope here?

However, it seems to me to be two-parted, both that the “normalize()”-function is very inefficient on this type of input, but also that neither NetSurf nor Duktape have any limits for duration or memory usage of a function like this.

The specific example shown here uses a complex series of left and right angle brackets to confuse the normalize-function, but I find it surprising that such a short HTML file can make the OOM killer take down my entire window manager.

Steps To Reproduce

- Build/Install NetSurf 3.11, for example from the Debian 13 repositories (`# apt install netsurf-gtk`)
- Enable Javascript in Preferences
- Open a page with some resource intensive JavaScript (For example, with the file ./normalize.html, run `$ netsurf-gtk file://$(pwd)/normalize.html`)

For example this HTML file:

<html>
    <head>
        <style>
            ><<>><><<>><>><<<<>><><><<>>>><<<<>><<><<>>><<><>>><>><<><<>><<>><<<<<<>>><>><><><><<>><><<<<>><>>><><><<><>>><><><><>><<<<>>>><>><><<<<<><><<<>>>>>>>>>><>>><<<<<<<<<<>>>>><><<<>>><>>>>>><>><<<<><<><>><<>><><<<>>>>>>>><<<>>>><<><<<<<><><><>><>><<<>><<<><><<<>>>>><><<>>>><>>><<<<<<<<>>><<<>>>><>>>>>><><>><><>><><>>>>><<>><<>>>><<>><><<>><><<><<>><><<<>>><<><><<<><>><<><<>><><<<<<<<<<<>><>><><<>>><>
        </style>
    </head>
<body>
    <script>
        document.head.normalize()
    </script>
</body>
</html>

Additional Information

Tested with NetSurf 3.11 on Debian(testing) and NixOS (unstable).
Requires JavaScript to be enabled.
I have not tested any other platforms.

Date Modified	Username	Field	Change
Issue History
2024-05-28 14:02	Felix Albrigtsen	New Issue

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