Received-SPF: softfail (google.com: domain of transitioning linux-kernel-owner@vger.kernel.org does not designate 23.128.96.19 as permitted sender) client-ip=23.128.96.19;
MIME-Version: 1.0
References: <20220608110734.2928245-1-tzungbi@kernel.org> <20220608110734.2928245-21-tzungbi@kernel.org>
In-Reply-To: <20220608110734.2928245-21-tzungbi@kernel.org>
From:   Guenter Roeck <groeck@google.com>
Date:   Wed, 8 Jun 2022 09:24:14 -0700
Message-ID: <CABXOdTdqguBzxcKWXm+tQJ-XGa_1J26bBJqPLiY7qn4gfn+czg@mail.gmail.com>
Subject: Re: [PATCH v3 20/23] platform/chrome: cros_ec_proto: handle empty
 payload in getting cmd mask
To:     Tzung-Bi Shih <tzungbi@kernel.org>
Cc:     Benson Leung <bleung@chromium.org>,
        Guenter Roeck <groeck@chromium.org>,
        "open list:CHROME HARDWARE PLATFORM SUPPORT" 
        <chrome-platform@lists.linux.dev>,
        linux-kernel <linux-kernel@vger.kernel.org>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Wed, Jun 8, 2022 at 4:08 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote:
>
> cros_ec_get_host_command_version_mask() expects to receive
> sizeof(struct ec_response_get_cmd_versions) from send_command().  The
> payload is valid only if the return value is positive.
>
> Return -EPROTO if send_command() returns 0 in
> cros_ec_get_host_command_version_mask().
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>

That answers my previous question.

Reviewed-by: Guenter Roeck <groeck@chromium.org>

> ---
> No v2.  New and separated from the original series.
>
>  drivers/platform/chrome/cros_ec_proto.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 6a5771361383..9e95f9e4b2f8 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -458,6 +458,11 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
>                 goto exit;
>         }
>
> +       if (ret == 0) {
> +               ret = -EPROTO;
> +               goto exit;
> +       }
> +
>         rver = (struct ec_response_get_cmd_versions *)msg->data;
>         *mask = rver->version_mask;
>         ret = 0;
> --
> 2.36.1.255.ge46751e96f-goog
>