Re: [PATCH 1/1] stmmac: bugfix oops on rmmod after ifconfig

[Andy Shevchenko]

On Mon, Apr 13, 2015 at 2:15 PM, Bryan O'Donoghue
<pure.logic@xxxxxxxxxxxxxxxxx> wrote:
> An oops exists in the flow of stmmac_release().
> phy_ethtool_get_wol() depends on phydev->drv which will be null in
> stmmac_dvr_remove after stmmac_mdio_unreg() completes.
>
> Steps to reproduce on Quark X1000:
>
> 1. ifconfig eth0 192.168.0.1
> 2. rmmod stmmac_pci
>
> This patch re-orders the calling of the unreg() functions so that
> stmmac_unreg_mdio() happens later in the release() routine thus avoiding the
> null pointer dereference.
>
> Signed-off-by: Bryan O'Donoghue <pure.logic@xxxxxxxxxxxxxxxxx>
> Reported-by: Dan O'Donovan <dan.odonovan@xxxxxxxxxx>

Shouldn't Fixes: tag be present here?

>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index a0ea84f..3ab3e4a8 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -2958,14 +2958,14 @@ int stmmac_dvr_remove(struct net_device *ndev)
>         priv->hw->dma->stop_tx(priv->ioaddr);
>
>         stmmac_set_mac(priv->ioaddr, false);
> -       if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
> -           priv->pcs != STMMAC_PCS_RTBI)
> -               stmmac_mdio_unregister(ndev);
>         netif_carrier_off(ndev);
>         unregister_netdev(ndev);
>         if (priv->stmmac_rst)
>                 reset_control_assert(priv->stmmac_rst);
>         clk_disable_unprepare(priv->stmmac_clk);
> +       if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
> +           priv->pcs != STMMAC_PCS_RTBI)
> +               stmmac_mdio_unregister(ndev);
>         free_netdev(ndev);
>
>         return 0;
> --
> 1.9.1
>
> --
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-- 
With Best Regards,
Andy Shevchenko
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