rocker_port_fdb_flush() is called by rocker_port_stp_update() which in
turn may be called with trans == SWITCHDEV_TRANS_PREPARE and then
trans == SWITCHDEV_TRANS_COMMIT from switchdev_port_attr_set() via
br_set_state().
When rocker_port_fdb_flush() is called with trans == SWITCHDEV_TRANS_PREPARE
it calls rocker_port_fdb_learn() for each entry in the FDB table which in
turn calls rocker_flow_tbl_bridge() which will allocate memory using
rocker_port_kzalloc(). rocker_port_fdb_learn() will then remove the entry
from the FDB table.
Then when rocker_port_fdb_learn() is called with
trans == SWITCHDEV_TRANS_PREPARE no calls are made to rocker_port_fdb_learn()
because there are no longer any entries present in the FDB table. Thus the
memory previously allocated by rocker_port_fdb_learn() is leaked resulting
in the kernel BUG() below.
Furthermore, it looks like the driver ends up with an incorrect view of the
fdb table as the FDB entries are purged from the driver's table but not the
hardware's table.
Fixes: c4f20321d968 ("rocker: support prepare-commit transaction model") Acked-by: Scott Feldman <sfeldma@gmail.com> Acked-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Simon Horman <simon.horman@netronome.com> Signed-off-by: David S. Miller <davem@davemloft.net>