Re: [PATCH 3/6] platform/chrome: cros_ec_proto: drop BUG_ON() in cros_ec_prepare_tx()

[Guenter Roeck]

On Thu, May 12, 2022 at 1:36 AM Tzung-Bi Shih <tzungbi@xxxxxxxxxx> wrote:
>
> It is overkill to crash the kernel if the given message is oversize.
>
> Drop the BUG_ON() and return -EINVAL instead.
>
> Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>

Reviewed-by: Guenter Roeck <groeck@xxxxxxxxxxxx>

> ---
>  drivers/platform/chrome/cros_ec_proto.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index 2d6d3fbfa905..9ce3374846ff 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -60,7 +60,8 @@ static int prepare_packet(struct cros_ec_device *ec_dev,
>         int i;
>         u8 csum = 0;
>
> -       BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size);
> +       if (msg->outsize + sizeof(*request) > ec_dev->dout_size)
> +               return -EINVAL;
>
>         out = ec_dev->dout;
>         request = (struct ec_host_request *)out;
> @@ -176,7 +177,9 @@ int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
>         if (ec_dev->proto_version > 2)
>                 return prepare_packet(ec_dev, msg);
>
> -       BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
> +       if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE)
> +               return -EINVAL;
> +
>         out = ec_dev->dout;
>         out[0] = EC_CMD_VERSION0 + msg->version;
>         out[1] = msg->command;
> --
> 2.36.0.512.ge40c2bad7a-goog
>