Re: [PATCH 1/4] test: firmware_class: report errors properly on failure

[Kees Cook]

On Tue, Dec 8, 2015 at 6:38 PM, Brian Norris
<computersforpeace@xxxxxxxxx> wrote:
> request_firmware() failures currently won't get reported at all (the
> error code is discarded). What's more, we get confusing messages, like:
>
>     # echo -n notafile > /sys/devices/virtual/misc/test_firmware/trigger_request
>     [ 8280.311856] test_firmware: loading 'notafile'
>     [ 8280.317042] test_firmware: load of 'notafile' failed: -2
>     [ 8280.322445] test_firmware: loaded: 0
>     # echo $?
>     0
>
> Report the failures via write() errors, and don't say we "loaded"
> anything.
>
> Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx>

Yeah, good called.

Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
>  lib/test_firmware.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/lib/test_firmware.c b/lib/test_firmware.c
> index 86374c1c49a4..841191061816 100644
> --- a/lib/test_firmware.c
> +++ b/lib/test_firmware.c
> @@ -65,14 +65,19 @@ static ssize_t trigger_request_store(struct device *dev,
>         release_firmware(test_firmware);
>         test_firmware = NULL;
>         rc = request_firmware(&test_firmware, name, dev);
> -       if (rc)
> +       if (rc) {
>                 pr_info("load of '%s' failed: %d\n", name, rc);
> -       pr_info("loaded: %zu\n", test_firmware ? test_firmware->size : 0);
> +               goto out;
> +       }
> +       pr_info("loaded: %zu\n", test_firmware->size);
> +       rc = count;
> +
> +out:
>         mutex_unlock(&test_fw_mutex);
>
>         kfree(name);
>
> -       return count;
> +       return rc;
>  }
>  static DEVICE_ATTR_WO(trigger_request);
>
> --
> 2.6.0.rc2.230.g3dd15c0
>



-- 
Kees Cook
Chrome OS & Brillo Security
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