CVE-2009-1265 kernel: af_rose/x25: Sanity check the maximum user frame size

[Eugene Teo <eugene () redhat com>]

{nr,rose,x25}_sendmsg() functions need to have sanity checks on the
packet size, otherwise the sizes can wrap and end up sending garbage.

http://bugzilla.kernel.org/show_bug.cgi?id=10423
http://git.kernel.org/linus/83e0bbcbe2145f160fbaa109b0439dae7f4a38a9
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2009-1265

This affects both 2.4.x and 2.6.x if CONFIG_{NETROM,ROSE,X25} are enabled.

Thanks, Eugene
-- 
Eugene Teo, RHCA, RHCSS / Red Hat Security Response Team