Re: [PATCH] iio: light: Add check for array bounds in veml6075_read_int_time_ms

[Javier Carrasco]

On Sun Feb 2, 2025 at 11:49 AM CET, Karan Sanghavi wrote:
> The array contains only 5 elements, but the index calculated by
> veml6075_read_int_time_index can range from 0 to 7,
> which could lead to out-of-bounds access. The check prevents this issue.
>
> Coverity Issue
> CID 1574309: (#1 of 1): Out-of-bounds read (OVERRUN)
> overrun-local: Overrunning array veml6075_it_ms of 5 4-byte
> elements at element index 7 (byte offset 31) using
> index int_index (which evaluates to 7)
>
> Fixes: 3b82f43238ae ("iio: light: add VEML6075 UVA and UVB light sensor driver")
> Signed-off-by: Karan Sanghavi <karansanghvi98@xxxxxxxxx>
> ---
>  drivers/iio/light/veml6075.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c
> index 05d4c0e9015d..a892330582f4 100644
> --- a/drivers/iio/light/veml6075.c
> +++ b/drivers/iio/light/veml6075.c
> @@ -210,7 +210,7 @@ static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val)
>
>  	guard(mutex)(&data->lock);
>  	int_index = veml6075_read_int_time_index(data);
> -	if (int_index < 0)
> +	if (int_index < 0 || int_index >= ARRAY_SIZE(veml6075_it_ms))
>  		return int_index;
>
>  	*val = veml6075_it_ms[int_index];
>
> ---
> base-commit: df4b2bbff898227db0c14264ac7edd634e79f755
> change-id: 20250202-outofboundsread1573409-378997439be1
>
> Best regards,


Hi Karan,

Thanks for your patch. That could never happen because the device does
not support those values: it only delivers values between 0 and 4 for
that field because it does not support more integration times.

Even though the check does not do anything in reality, it does not hurt
either, and I would like to avoid future noise from coverity.

Reviewed-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>