Re: [PATCH stable 4.9] net: mdio-mux: fix unbalanced put_device

[Greg KH]

On Wed, Nov 17, 2021 at 10:03:08AM -0800, Florian Fainelli wrote:
> From: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
> 
> commit 60f786525032432af1b7d9b8935cb12936244ccd upstream
> 
> mdio_mux_uninit() call put_device (unconditionally) because of
> of_mdio_find_bus() in mdio_mux_init.
> But of_mdio_find_bus is only called if mux_bus is empty.
> If mux_bus is set, mdio_mux_uninit will print a "refcount_t: underflow"
> trace.
> 
> This patch add a get_device in the other branch of "if (mux_bus)".
> 
> Signed-off-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
> Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
> Note: this patch did not get any fixes tag, but it does fix issues
> introduced by  fdf3b78df4d2 ("mdio: mux: Correct mdio_mux_init error
> path issues").

Now queued up, thanks.

greg k-h