On Thu, Sep 30, 2021 at 2:28 PM Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> This check has a signedness bug and does not work. If "length" is
> larger than "PAGE_SIZE" then "PAGE_SIZE - length" is not negative
> but instead it is a large unsigned value. Fortunately, Takashi Iwai
> changed this code to use scnprint() instead of snprintf() so now
> "length" is never larger than "PAGE_SIZE - 1" and the check can be
> removed.
>
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
> drivers/thermal/intel/int340x_thermal/int3400_thermal.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> index 19926beeb3b7..8502b7d8df89 100644
> --- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> +++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
> @@ -129,11 +129,10 @@ static ssize_t available_uuids_show(struct device *dev,
>
> for (i = 0; i < INT3400_THERMAL_MAXIMUM_UUID; i++) {
> if (priv->uuid_bitmap & (1 << i))
> - if (PAGE_SIZE - length > 0)
> - length += scnprintf(&buf[length],
> - PAGE_SIZE - length,
> - "%s\n",
> - int3400_thermal_uuids[i]);
> + length += scnprintf(&buf[length],
> + PAGE_SIZE - length,
> + "%s\n",
> + int3400_thermal_uuids[i]);
> }
>
> return length;
> --
Applied as 5.16 material, thanks!
