Revert "net: mdiobus: Fix memory leak in __mdiobus_register"

commit 10eff1f578 upstream.

This reverts commit ab609f25d1.

This patch is correct in the sense that we _should_ call device_put() in
case of device_register() failure, but the problem in this code is more
vast.

We need to set bus->state to UNMDIOBUS_REGISTERED before calling
device_register() to correctly release the device in mdiobus_free().
This patch prevents us from doing it, since in case of device_register()
failure put_device() will be called 2 times and it will cause UAF or
something else.

Also, Reported-by: tag in revered commit was wrong, since syzbot
reported different leak in same function.

Link: https://lore.kernel.org/netdev/20210928092657.GI2048@kadam/
Acked-by: Yanfei Xu <yanfei.xu@windriver.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/f12fb1faa4eccf0f355788225335eb4309ff2599.1633024062.git.paskripkin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pavel Skripkin 2021-09-30 20:49:42 +03:00 committed by Greg Kroah-Hartman
parent d4f5ca0a44
commit fdbffd95c4

View file

@ -354,7 +354,6 @@ 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;
}