Alternative solution for problem found by Linux Driver Verification
project (linuxtesting.org).
As it noted in the comment before the br_handle_frame_finish
function, this function should be called under rcu_read_lock.
The problem callgraph:
br_dev_xmit -> br_nf_pre_routing_finish_bridge_slow ->
-> br_handle_frame_finish -> br_port_get_rcu -> rcu_dereference
And in this case there is no read-lock section.
Reported-by: Denis Efremov <yefremov.denis@gmail.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
c03307eab6