nvmet-rdma: Fix NULL deref when setting pi_enable and traddr INADDR_ANY

When setting port traddr to INADDR_ANY, the listening cm_id->device
is NULL. The associate IB device is known only when a connect request
event arrives, so checking T10-PI device capability should be done
at this stage.

Fixes: b09160c3 ("nvmet-rdma: add metadata/T10-PI support")
Signed-off-by: NIsrael Rukshin <israelr@nvidia.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NMax Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

drivers/nvme/target/rdma.c

@@ -1220,6 +1220,14 @@ nvmet_rdma_find_get_device(struct rdma_cm_id *cm_id)
 	}
 	ndev->inline_data_size = nport->inline_data_size;
 	ndev->inline_page_count = inline_page_count;
+
+	if (nport->pi_enable && !(cm_id->device->attrs.device_cap_flags &
+				  IB_DEVICE_INTEGRITY_HANDOVER)) {
+		pr_warn("T10-PI is not supported by device %s. Disabling it\n",
+			cm_id->device->name);
+		nport->pi_enable = false;
+	}
+
 	ndev->device = cm_id->device;
 	kref_init(&ndev->ref);
 
@@ -1855,14 +1863,6 @@ static int nvmet_rdma_enable_port(struct nvmet_rdma_port *port)
 		goto out_destroy_id;
 	}
 
-	if (port->nport->pi_enable &&
-	    !(cm_id->device->attrs.device_cap_flags &
-	      IB_DEVICE_INTEGRITY_HANDOVER)) {
-		pr_err("T10-PI is not supported for %pISpcs\n", addr);
-		ret = -EINVAL;
-		goto out_destroy_id;
-	}
-
 	port->cm_id = cm_id;
 	return 0;