Re: [PATCH next] platform/x86: oxpec: Add a lower bounds check in oxp_psy_ext_set_prop()

[Antheas Kapenekakis]

On Fri, 2 May 2025 at 10:40, Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote:
>
> The "val->intval" variable is an integer which comes from the user.  This
> code has an upper bounds check but the lower bounds check was
> accidentally omitted.  The write_to_ec() take a u8 value as a parameter
> so negative values would be truncated to positive values in the 0-255
> range.
>
> Return -EINVAL if the user passes a negative value.
>
> Fixes: 202593d1e86b ("platform/x86: oxpec: Add charge threshold and behaviour to OneXPlayer")

Reviewed-by: Antheas Kapenekakis <lkml@xxxxxxxxxxx>

Thanks,
Antheas

> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> ---
>  drivers/platform/x86/oxpec.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/x86/oxpec.c b/drivers/platform/x86/oxpec.c
> index 4b48f4571b09..de70ca7e8493 100644
> --- a/drivers/platform/x86/oxpec.c
> +++ b/drivers/platform/x86/oxpec.c
> @@ -582,7 +582,7 @@ static int oxp_psy_ext_set_prop(struct power_supply *psy,
>
>         switch (psp) {
>         case POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD:
> -               if (val->intval > 100)
> +               if (val->intval < 0 || val->intval > 100)
>                         return -EINVAL;
>                 return write_to_ec(OXP_X1_CHARGE_LIMIT_REG, val->intval);
>         case POWER_SUPPLY_PROP_CHARGE_BEHAVIOUR:
> --
> 2.47.2
>