[ Upstream commit 1d36cb479f ]
when use dst_get_neighbour to get neighbour, we need
rcu_read_lock to protect, since dst_get_neighbour uses
rcu_dereference.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>