hidp bug concerning ctrl_sk sock

With reference to bug https://bugzilla.kernel.org/show_bug.cgi?id=50541
it seems to me that the hidp driver has a problem in the hidp_session()
function.

The sock structure pointed to by ctrl_sk is being freed from under the
functions feet (as far as I can see), causing this function to crash.
Shouldn't a lock_sock or sock_hold be necessary to keep the sock
structure around until hidp_session has finished with it?