[PATCH net] net: marvell: prestera: fix brige port operation

[Volodymyr Mytnyk]

From: Volodymyr Mytnyk <vmytnyk@xxxxxxxxxxx>

- handle SWITCHDEV_BRPORT_[UN]OFFLOADED events for
  switchdev_bridge_port_offload to avoid fail return.
- fix error path handling in prestera_bridge_port_join to
  fix double free issue (see below).

Trace:
  Internal error: Oops: 96000044 [#1] SMP
  Modules linked in: prestera_pci prestera uio_pdrv_genirq
  CPU: 1 PID: 881 Comm: ip Not tainted 5.15.0 #1
  pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : prestera_bridge_destroy+0x2c/0xb0 [prestera]
  lr : prestera_bridge_port_join+0x2cc/0x350 [prestera]
  sp : ffff800011a1b0f0
  ...
  x2 : ffff000109ca6c80 x1 : dead000000000100 x0 : dead000000000122
   Call trace:
  prestera_bridge_destroy+0x2c/0xb0 [prestera]
  prestera_bridge_port_join+0x2cc/0x350 [prestera]
  prestera_netdev_port_event.constprop.0+0x3c4/0x450 [prestera]
  prestera_netdev_event_handler+0xf4/0x110 [prestera]
  raw_notifier_call_chain+0x54/0x80
  call_netdevice_notifiers_info+0x54/0xa0
  __netdev_upper_dev_link+0x19c/0x380

Fixes: 2f5dc00f7a3e ("net: bridge: switchdev: let drivers inform which bridge ports are offloaded")
Signed-off-by: Volodymyr Mytnyk <vmytnyk@xxxxxxxxxxx>
---
 drivers/net/ethernet/marvell/prestera/prestera_switchdev.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c b/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
index 3ce6ccd0f539..f1bc6699ec8b 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_switchdev.c
@@ -497,8 +497,8 @@ int prestera_bridge_port_join(struct net_device *br_dev,
 
 	br_port = prestera_bridge_port_add(bridge, port->dev);
 	if (IS_ERR(br_port)) {
-		err = PTR_ERR(br_port);
-		goto err_brport_create;
+		prestera_bridge_put(bridge);
+		return PTR_ERR(br_port);
 	}
 
 	err = switchdev_bridge_port_offload(br_port->dev, port->dev, NULL,
@@ -519,8 +519,6 @@ int prestera_bridge_port_join(struct net_device *br_dev,
 	switchdev_bridge_port_unoffload(br_port->dev, NULL, NULL, NULL);
 err_switchdev_offload:
 	prestera_bridge_port_put(br_port);
-err_brport_create:
-	prestera_bridge_put(bridge);
 	return err;
 }
 
@@ -1123,6 +1121,9 @@ static int prestera_switchdev_blk_event(struct notifier_block *unused,
 						     prestera_netdev_check,
 						     prestera_port_obj_attr_set);
 		break;
+	case SWITCHDEV_BRPORT_OFFLOADED:
+	case SWITCHDEV_BRPORT_UNOFFLOADED:
+		return NOTIFY_DONE;
 	default:
 		err = -EOPNOTSUPP;
 	}
-- 
2.7.4