scsi: mpt3sas: Fix NULL pointer access in mpt3sas_transport_port_add()

Port is allocated by sas_port_alloc_num() and rphy is allocated by either
sas_end_device_alloc() or sas_expander_alloc(), all of which may return
NULL. So we need to check the rphy to avoid possible NULL pointer access.

If sas_rphy_add() returned with failure, rphy is set to NULL. We would
access the rphy in the following lines which would also result NULL pointer
access.

Fixes: 78316e9 ("scsi: mpt3sas: Fix possible resource leaks in mpt3sas_transport_port_add()")
Signed-off-by: Wenchao Hao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Acked-by: Sathya Prakash Veerichetty <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: wenchao-hao

drivers/scsi/mpt3sas/mpt3sas_transport.c

@@ -785,7 +785,7 @@ mpt3sas_transport_port_add(struct MPT3SAS_ADAPTER *ioc, u16 handle,
 		goto out_fail;
 	}
 	port = sas_port_alloc_num(sas_node->parent_dev);
-	if ((sas_port_add(port))) {
+	if (!port || (sas_port_add(port))) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
 			__FILE__, __LINE__, __func__);
 		goto out_fail;
@@ -824,13 +824,20 @@ mpt3sas_transport_port_add(struct MPT3SAS_ADAPTER *ioc, u16 handle,
 			    mpt3sas_port->remote_identify.sas_address;
 	}
 
+	if (!rphy) {
+		ioc_err(ioc, "failure at %s:%d/%s()!\n",
+			__FILE__, __LINE__, __func__);
+		goto out_delete_port;
+	}
+
 	rphy->identify = mpt3sas_port->remote_identify;
 
 	if ((sas_rphy_add(rphy))) {
 		ioc_err(ioc, "failure at %s:%d/%s()!\n",
 			__FILE__, __LINE__, __func__);
 		sas_rphy_free(rphy);
 		rphy = NULL;
+		goto out_delete_port;
 	}
 
 	if (mpt3sas_port->remote_identify.device_type == SAS_END_DEVICE) {
@@ -857,7 +864,10 @@ mpt3sas_transport_port_add(struct MPT3SAS_ADAPTER *ioc, u16 handle,
 		    rphy_to_expander_device(rphy), hba_port->port_id);
 	return mpt3sas_port;
 
- out_fail:
+out_delete_port:
+	sas_port_delete(port);
+
+out_fail:
 	list_for_each_entry_safe(mpt3sas_phy, next, &mpt3sas_port->phy_list,
 	    port_siblings)
 		list_del(&mpt3sas_phy->port_siblings);