NTB: fix possible name leak in ntb_register_device()

If device_register() fails in ntb_register_device(), the device name
allocated by dev_set_name() should be freed. As per the comment in
device_register(), callers should use put_device() to give up the
reference in the error path. So fix this by calling put_device() in the
error path so that the name can be freed in kobject_cleanup().

As a result of this, put_device() in the error path of
ntb_register_device() is removed and the actual error is returned.

Fixes: a1bd3ba ("NTB: Add NTB hardware abstraction layer")
Signed-off-by: Yang Yingliang <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
Reviewed-by: Manivannan Sadhasivam <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[mani: reworded commit message]
Signed-off-by: Manivannan Sadhasivam <[email protected]>

Author: Yang Yingliang

drivers/ntb/core.c

@@ -100,6 +100,8 @@ EXPORT_SYMBOL(ntb_unregister_client);
 
 int ntb_register_device(struct ntb_dev *ntb)
 {
+	int ret;
+
 	if (!ntb)
 		return -EINVAL;
 	if (!ntb->pdev)
@@ -120,7 +122,11 @@ int ntb_register_device(struct ntb_dev *ntb)
 	ntb->ctx_ops = NULL;
 	spin_lock_init(&ntb->ctx_lock);
 
-	return device_register(&ntb->dev);
+	ret = device_register(&ntb->dev);
+	if (ret)
+		put_device(&ntb->dev);
+
+	return ret;
 }
 EXPORT_SYMBOL(ntb_register_device);
 

drivers/pci/endpoint/functions/pci-epf-vntb.c

@@ -1264,15 +1264,11 @@ static int pci_vntb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	ret = ntb_register_device(&ndev->ntb);
 	if (ret) {
 		dev_err(dev, "Failed to register NTB device\n");
-		goto err_register_dev;
+		return ret;
 	}
 
 	dev_dbg(dev, "PCI Virtual NTB driver loaded\n");
 	return 0;
-
-err_register_dev:
-	put_device(&ndev->ntb.dev);
-	return -EINVAL;
 }
 
 static struct pci_device_id pci_vntb_table[] = {