[CVE-2011-2498] PTE accounting DOS

[Andy Whitcroft]

CVE-2011-2498
	PTE pages are invisible memory user. A local, unprivileged user
	could leverage this flaw to trigger a denial of service. AFAIK,
	this was introduced in a63d83f427f (v2.6.36-rc1), fixed in
	f755a042d (v2.6.39-rc6).

This was introduced in natty and fixes for this have hit natty and
later via mainline and stable.  Following this email is a patch for
natty/ti-omap4, this is a simple cherry-pick from the mainline fix.

Proposing for natty/ti-omap4.

-apw