be2net: Fix invocation of be_close() after be_clear()

In the EEH error recovery path, when a permanent failure occurs,
we clean up adapter structure (i.e. destroy queues etc) by calling
be_clear() and return PCI_ERS_RESULT_DISCONNECT.
After this the stack tries to remove device from bus and calls
be_remove() which invokes netdev_unregister()->be_close().
be_close() operating on destroyed queues results in a
NULL dereference.

This patch fixes this problem by introducing a flag to keep track
of the setup state.
Signed-off-by: Kalesh AP <kalesh.purayil@emulex.com>
Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/emulex/benet/be.h

@@ -374,6 +374,7 @@ enum vf_state {
 #define BE_FLAGS_NAPI_ENABLED			(1 << 9)
 #define BE_FLAGS_QNQ_ASYNC_EVT_RCVD		(1 << 11)
 #define BE_FLAGS_VXLAN_OFFLOADS			(1 << 12)
+#define BE_FLAGS_SETUP_DONE			(1 << 13)
 
 #define BE_UC_PMAC_COUNT			30
 #define BE_VF_UC_PMAC_COUNT			2

drivers/net/ethernet/emulex/benet/be_main.c

@@ -2726,6 +2726,12 @@ static int be_close(struct net_device *netdev)
 	struct be_eq_obj *eqo;
 	int i;
 
+	/* This protection is needed as be_close() may be called even when the
+	 * adapter is in cleared state (after eeh perm failure)
+	 */
+	if (!(adapter->flags & BE_FLAGS_SETUP_DONE))
+		return 0;
+
 	be_roce_dev_close(adapter);
 
 	if (adapter->flags & BE_FLAGS_NAPI_ENABLED) {
@@ -3056,6 +3062,7 @@ static int be_clear(struct be_adapter *adapter)
 	be_clear_queues(adapter);
 
 	be_msix_disable(adapter);
+	adapter->flags &= ~BE_FLAGS_SETUP_DONE;
 	return 0;
 }
 
@@ -3560,6 +3567,7 @@ static int be_setup(struct be_adapter *adapter)
 		adapter->phy.fc_autoneg = 1;
 
 	be_schedule_worker(adapter);
+	adapter->flags |= BE_FLAGS_SETUP_DONE;
 	return 0;
 err:
 	be_clear(adapter);