Re: [PATCH RFC 0/4] Add firmware signature file check

[Ming Lei]

On Tue, Nov 6, 2012 at 3:03 PM, Takashi Iwai <tiwai@xxxxxxx> wrote:
>
> Yeah, it's just uncovered in the patch.  As a easy solution, apply the
> patch like below to disallow the udev fw loading when signature check
> is enforced.
>
>
> thanks,
>
> Takashi
>
> ---
> diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
> index 575bc4c..93121c3 100644
> --- a/drivers/base/firmware_class.c
> +++ b/drivers/base/firmware_class.c
> @@ -912,6 +912,13 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
>                 goto handle_fw;
>         }
>
> +       /* signature check isn't handled via udev fw loading */
> +       if (sig_enforce) {
> +               fw_load_abort(fw_priv);
> +               direct_load = 1;
> +               goto handle_fw;
> +       }
> +

The above might be wrong if the firmware file doesn't exist in default
search paths. You should skip loading from user space only if
verify_signature() returns false. And the udev loading should be
resorted to if there is no such firmware file in default search paths.

>         /* fall back on userspace loading */
>         buf->fmt = PAGE_BUF;
>


Thanks,
-- 
Ming Lei
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/