382681 - Unsafe DOM mutation events in scrollable frame

Status: RESOLVED FIXED

Description

[Vlad Sukhoy]

Created attachment 266803 [details]
test case for mutation events in scrollable frame

Using DOM mutation events it is possible to trash the UI so that the browser is unresponsive. See related bug 382568 and bug 355548 for more related test cases.

Comment 1

[Martijn Wargers (dead)]

I get 100% cpu on trunk also. You mean that shouldn't happen?

Comment 2

[Vlad Sukhoy]

if the UI is still responsive, then it is not so bad. On branches the UI stop working, and that is equivalent to "denial of service".

Comment 3

[Vlad Sukhoy]

Oh, indeed, the UI gets unresponsive on trunk too.

Comment 4

[Olli Pettay [:smaug]]

On linux (trunk/1.8) I get endless loop of JS's "too much recursion"s
(which as such isn't Security-Sensitive, IMO). 
bug 382568 and bug 355548 are crashers.

Comment 5

[Vlad Sukhoy]

IMO, it is security sensitive because it suggests a pattern to exploit things in a way similar to those.
Should we file a metabug or whatever to keep these guys together?

Comment 6

[Vlad Sukhoy]

Created attachment 267625 [details]
a (better) testcase for mutation events in scrollable frame

Ok, this testcase does crash 1.8 and 1.8.0 on MacOS for me it was just a matter of skipping a couple of legitimate mutation events and doing nasty stuff on the vulnerable one.

Comment 7

[Vlad Sukhoy]

Crashes on Linux too. Severity elevated, title adjusted...

Comment 8

[Olli Pettay [:smaug]]

Created attachment 267939 [details] [diff] [review]
proposed patch

Just don't propagate any mutation events from native anonymous content.
IsAnonymousForEvents() is needed because XUL has its own implementation
for IsNativeAnonymous().
This fixes also Bug 382568.

Comment 9

[Olli Pettay [:smaug]]

attachment 267939 [details] [diff] [review] fixes also bug 382700.
Note, I didn't change nsGenericDOMDataNode::HandleDOMEvent to
check nativeness, because it doesn't implement SetNativeAnonymous
properly and native anon text nodes are AFAIK always inside native
anonymous elements.
(This all ofc works properly on trunk.)

Comment 10

[Daniel Veditz [:dveditz]]

Comment on attachment 267939 [details] [diff] [review]
proposed patch

approved for 1.8.1.5 and 1.8.0.13, a=dveditz for release-drivers

Comment 11

[Olli Pettay [:smaug]]

Checked in to branches

Comment 12

[juan becerra [:juanb]]

Verified on Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en-US; rv:1.8.0.13pre) Gecko/20070810 Firefox/1.5.0.13pre

Fx15012 crashed but Fx15013pre did not.