[ Upstream commit 84a7c0b1 ]

dns_query() credulously assumes that keys are null-terminated and
returns a copy of a memory block that is off by one.
Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>