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

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/host/fabrics.c

@@ -872,6 +872,15 @@ nvmf_create_ctrl(struct device *dev, const char *buf, size_t count)
 		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;