Re: [PATCH] net: mdiobus: Fix memory leak in __mdiobus_register

[Denis Efremov]

Hi,

Just want to note that highly likely this patch reintroduces
CVE-2019-12819 that was fixed in commit
6ff7b060535e ("mdio_bus: Fix use-after-free on device_register fails")
and added by the same patch in commit
0c692d07842a ("drivers/net/phy/mdio_bus.c: call put_device on device_register() failure")

>  drivers/net/phy/mdio_bus.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index 53f034fc2ef7..6f4b4e5df639 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -537,6 +537,7 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
>  	err = device_register(&bus->dev);
>  	if (err) {
>  		pr_err("mii_bus %s failed to register\n", bus->id);
> +		put_device(&bus->dev);
>  		return -EINVAL;
>  	}


Thanks,
Denis