[CVE-2011-1927] fragment storm vunerability

[Andy Whitcroft]

CVE-2011-1927
	In function icmp_send() (net/ipv4/icmp.c), the parameter passed
	to dev_net() function is not properly validated. This can lead
	to a NULL pointer dereference that crashes the kernel.

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

Proposing for maverick, maverick/ti-omap4 and natty/ti-omap4.

-apw