[CVE-2010-4157] gdth: integer overflow in ioctl

[Andy Whitcroft]

CVE-2010-4157

	Integer overflow in the ioc_general function in drivers/scsi/gdth.c
	in the Linux kernel before 2.6.36.1 on 64-bit platforms allows
	local users to cause a denial of service (memory corruption)
	or possibly have unspecified other impact via a large argument
	in an ioctl call.

This was fixed before Natty opened, and has already hit Maverick and
Lucid via the upstream stable process.  The upstream fix cherry-picks
back to Karmic and Hardy unchanged.  I have backported this fix to
Dapper as well; including checks for additional parameters from
userspace (which are validated in other ways in Hardy and later).

Two patches follow, one for Dapper, and a second for Hardy and Karmic.

-apw