Re: [PATCH v2] net: macb: fix use after free on rmmod

[Nicolas Ferre]

On 08/09/2021 at 21:02, Tong Zhang wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> plat_dev->dev->platform_data is released by platform_device_unregister(),
> use of pclk and hclk is a use-after-free. Since device unregister won't
> need a clk device we adjust the function call sequence to fix this issue.
>
> [   31.261225] BUG: KASAN: use-after-free in macb_remove+0x77/0xc6 [macb_pci]
> [   31.275563] Freed by task 306:
> [   30.276782]  platform_device_release+0x25/0x80
>
> Suggested-by: Nicolas Ferre <Nicolas.Ferre@xxxxxxxxxxxxx>
> Signed-off-by: Tong Zhang <ztong0001@xxxxxxxxx>

Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>

Thanks Tong Zhang.
Regards,
  Nicolas

> ---
> v2: switch lines to fix the issue instead
>
>   drivers/net/ethernet/cadence/macb_pci.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb_pci.c b/drivers/net/ethernet/cadence/macb_pci.c
> index 8b7b59908a1a..f66d22de5168 100644
> --- a/drivers/net/ethernet/cadence/macb_pci.c
> +++ b/drivers/net/ethernet/cadence/macb_pci.c
> @@ -111,9 +111,9 @@ static void macb_remove(struct pci_dev *pdev)
>          struct platform_device *plat_dev = pci_get_drvdata(pdev);
>          struct macb_platform_data *plat_data = dev_get_platdata(&plat_dev->dev);
>
> -       platform_device_unregister(plat_dev);
>          clk_unregister(plat_data->pclk);
>          clk_unregister(plat_data->hclk);
> +       platform_device_unregister(plat_dev);
>   }
>
>   static const struct pci_device_id dev_id_table[] = {
> --
> 2.25.1


--
Nicolas Ferre