409718 - Pages with many float:left and clear:both CSS styles create denial of service

Status: RESOLVED DUPLICATE of bug 320378

(Core :: Layout: Floats, defect)

Description

[David Bartley]

User-Agent:       Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.8) Gecko/20071004 Iceweasel/2.0.0.8 (Debian-2.0.0.8-1)
Build Identifier: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.8) Gecko/20071004 Iceweasel/2.0.0.8 (Debian-2.0.0.8-1)

Pages with many float:left and clear:both CSS styles create a denial of service situation as 100% CPU is used and all other tabs/windows are unusable. The page does render eventually, though the rendering time is at least quadratic in the number of float/clear pairs.

Reproducible: Always

Steps to Reproduce:
Using firefox/mozilla, navigate to http://csclub.uwaterloo.ca/~dtbartle/clear.html.
Actual Results:  
Firefox becomes unresponsive; 100% CPU used.

Expected Results:  
A series of foo's are displayed.

Beta 1 of firefox 3.0 (from ubuntu hardy) also hangs.

Comment 1

[Martijn Wargers (dead)]

It seems to me this could have been fixed with the fix from bug 320378.
Could you perhaps test with current trunk build?
http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/

In any case, this is not a security issue.

Comment 2

[Martijn Wargers (dead)]

I have builds from 2007-11-28 and 2007-12-04.
With the 2007-11-28 build, I can see the bug, but with the 2007-12-04 build, I cannot. So I think this is basically bug 320378.