dpaa2-switch: check if the port priv is valid

Before accessing the port private structure make sure that there is
still a non-NULL pointer there. A NULL pointer access can happen when we
are on the remove path, some switch ports are unregistered and some are
in the process of unregistering.
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c

@@ -394,6 +394,7 @@ static int dpaa2_switch_dellink(struct ethsw_core *ethsw, u16 vid)
 
 	for (i = 0; i < ethsw->sw_attr.num_ifs; i++) {
 		ppriv_local = ethsw->ports[i];
+		if (ppriv_local)
 			ppriv_local->vlans[vid] = 0;
 	}
 
@@ -1896,9 +1897,11 @@ static int dpaa2_switch_port_del_vlan(struct ethsw_port_priv *port_priv, u16 vid
 		/* Delete VLAN from switch if it is no longer configured on
 		 * any port
 		 */
-		for (i = 0; i < ethsw->sw_attr.num_ifs; i++)
-			if (ethsw->ports[i]->vlans[vid] & ETHSW_VLAN_MEMBER)
+		for (i = 0; i < ethsw->sw_attr.num_ifs; i++) {
+			if (ethsw->ports[i] &&
+			    ethsw->ports[i]->vlans[vid] & ETHSW_VLAN_MEMBER)
 				return 0; /* Found a port member in VID */
+		}
 
 		ethsw->vlans[vid] &= ~ETHSW_VLAN_GLOBAL;