nvme-fabrics: verify that a controller returns the correct NQN

Signed-off-by: Christoph Hellwig <[e-mail]>
Reviewed-by: Sagi Grimberg <[e-mail]>
Reviewed-by: Johannes Thumshirn <[e-mail]>
Signed-off-by: Sagi Grimberg <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/nvme/host/fabrics.c

···
 		goto out_unlock;
 	}
 
+	if (strcmp(ctrl->subnqn, opts->subsysnqn)) {
+		dev_warn(ctrl->device,
+			"controller returned incorrect NQN: \"%s\".\n",
+			ctrl->subnqn);
+		mutex_unlock(&nvmf_transports_mutex);
+		ctrl->ops->delete_ctrl(ctrl);
+		return ERR_PTR(-EINVAL);
+	}
+
 	mutex_unlock(&nvmf_transports_mutex);
 	return ctrl;