On 3/23/2019 4:50 AM, Parav Pandit wrote:
> device_register() performs put_device() if device_add() fails.
> This balances with device_initialize().
>
> mdev core performing put_device() when device_register() fails,
> is an error that puts already released device again.
> Therefore, don't put the device on error.
>
device_add() on all errors doesn't call put_device(dev). It releases
reference to its parent, put_device(parent), but not the device itself,
put_device(dev).
Thanks,
Kirti
> Fixes: 7b96953bc640 ("vfio: Mediated device Core driver")
> Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
> ---
> drivers/vfio/mdev/mdev_core.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
> index 0212f0e..3e5880a 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -318,10 +318,8 @@ int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid)
> dev_set_name(&mdev->dev, "%pUl", uuid.b);
>
> ret = device_register(&mdev->dev);
> - if (ret) {
> - put_device(&mdev->dev);
> + if (ret)
> goto mdev_fail;
> - }
>
> ret = mdev_device_create_ops(kobj, mdev);
> if (ret)
>
