Re: [PATCH v2 1/2] Revert "net: mdiobus: Fix memory leak in __mdiobus_register"

[Xu, Yanfei]

On 9/29/21 4:39 AM, Pavel Skripkin wrote:
> This reverts commit ab609f25d19858513919369ff3d9a63c02cd9e2e.
>
> 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/
> Cc: Yanfei Xu<yanfei.xu@xxxxxxxxxxxxx>
> Signed-off-by: Pavel Skripkin<paskripkin@xxxxxxxxx>
> ---
>
> Changes in v2:
>          Added this revert


Acked-by: Yanfei Xu<yanfei.xu@xxxxxxxxxxxxx>

Thanks,
Yanfei