Bug 14319 – Move the Selection object out of the JS bindings

• Status: RESOLVED
• Resolution: FIXED
• Component: WebCore JavaScript

[Sam Weinig]

Forthcoming patch moves the Selection object out of the JS binding.  I have renamed the class DOMSelection to avoid a name clash, but this is not necessarily a long term solution.

[Sam Weinig]

Created attachment 15189 [details]
patch

[Geoffrey Garen]

Assuming disconnectFrame() gets called somewhere, DOMSelection needs to NULL check m_frame in each of its member functions.

+void DOMSelection::disconnectFrame()

I don't see any callers to this function. That means that, once the frame is destroyed, referencing its DOMSelection will read/write freed memory, right?

I believe this used to be called by Window::disconnectFrame(). Who should call it now?

+        mutable RefPtr<DOMSelection> m_selection;

Should probably call this m_DOMSelection to distinguish form WebCore::Selection.

There seems to be a cross-frame security problem here. Once I have a window's DOMSelection object, I can read the current selection in the window even if a new document from a new domain is loaded. I can't tell if your patch introduced this bug or not, but it's pretty serious.

r- for everything but the rename.

[Sam Weinig]

Created attachment 15210 [details]
updated patch

[Geoffrey Garen]

Comment on attachment 15210 [details]
updated patch

+        return "";

A different way to do this is to return String(), which gives you the null string. I'm not sure which we want here -- null string or empty string -- though. Empty seems fine.

This patch doesn't fix the security problem, but, like I said, I don't think it introduced the problem, either. Can you file a new bug about it?

One solution to the security problem would be to call DOMSelection::disconnectFrame inside Window::clear. Another solution would be to include isSafeScript checks in the JSSelection object.

[Sam Weinig]

Landed in r23842.  I will open another bug for issue Geoff pointed out.