Subject: Re: [PATCH net v3] net: ravb: Fix possible UAF bug in ravb_remove

From: Lee Jones <[email-masked]>
Date: Mon, 10 Jul 2023 12:42:53 +0100

On Sun, 12 Mar 2023, Zheng Wang wrote:

> In ravb_probe, priv->work was bound with ravb_tx_timeout_work.
> If timeout occurs, it will start the work. And if we call
> ravb_remove without finishing the work, there may be a
> use-after-free bug on ndev.
> 
> Fix it by finishing the job before cleanup in ravb_remove.
> 
> Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
> Signed-off-by: Zheng Wang <[email-masked]>
> Reviewed-by: Sergey Shtylyov <[email-masked]>
> ---
> v3:
> - fix typo in commit message
> v2:
> - stop dev_watchdog so that handle no more timeout work suggested by Yunsheng Lin,
> add an empty line to make code clear suggested by Sergey Shtylyov
> ---
>  drivers/net/ethernet/renesas/ravb_main.c | 4 ++++
>  1 file changed, 4 insertions(+)

For better or worse, it looks like this issue was assigned a CVE.

Are we expecting v4 or was it resolved in another way?

> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> index 0f54849a3823..eb63ea788e19 100644
> --- a/drivers/net/ethernet/renesas/ravb_main.c
> +++ b/drivers/net/ethernet/renesas/ravb_main.c
> @@ -2892,6 +2892,10 @@ 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);
> +	
>  	/* Stop PTP Clock driver */
>  	if (info->ccc_gac)
>  		ravb_ptp_stop(ndev);
> -- 
> 2.25.1
> 

-- 
Lee Jones [李琼斯]