Re: [PATCH] mdio_bus: Fix use-after-free on device_register fails

[David Miller]

From: Yue Haibing <yuehaibing@xxxxxxxxxx>
Date: Thu, 21 Feb 2019 22:42:01 +0800

> From: YueHaibing <yuehaibing@xxxxxxxxxx>
> 
> KASAN has found use-after-free in fixed_mdio_bus_init,
> commit 0c692d07842a ("drivers/net/phy/mdio_bus.c: call
> put_device on device_register() failure") call put_device()
> while device_register() fails,give up the last reference
> to the device and allow mdiobus_release to be executed
> ,kfreeing the bus. However in most drives, mdiobus_free
> be called to free the bus while mdiobus_register fails.
> use-after-free occurs when access bus again, this patch
> revert it to let mdiobus_free free the bus.
> 
> KASAN report details as below:
 ...
> Fixes: 0c692d07842a ("drivers/net/phy/mdio_bus.c: call put_device on device_register() failure")
> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>

Applied and queued up for -stable, thanks.