Re: [PATCH v4] net: ravb: Fix possible UAF bug in ravb_remove

From: Jakub Kicinski
Date: Tue Jul 25 2023 - 23:19:58 EST


On Tue, 25 Jul 2023 11:00:26 +0800 Zheng Wang wrote:
> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 4d6b3b7d6abb..ce2da5101e51 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -2885,6 +2885,9 @@ static int ravb_remove(struct platform_device *pdev)
> struct ravb_private *priv = netdev_priv(ndev);
> const struct ravb_hw_info *info = priv->info;
>
> + netif_carrier_off(ndev);
> + netif_tx_disable(ndev);
> + cancel_work_sync(&priv->work);

Still racy, the carrier can come back up after canceling the work.
But whatever, this is a non-issue in the first place.
The fact that ravb_tx_timeout_work doesn't take any locks seems much
more suspicious.