Re: [PATCH v2] iio: pressure: bmp280: fix out-of-bounds access in sampling frequency lookup

On Tue, 11 Aug 2026 10:52:53 +0800
Hui Su <sh_def-9Onoh4P/[email protected]> wrote:

> The sampling frequency tables store each frequency as an integer part and
> a fractional part in micro units. num_sampling_freq_avail is initialized
> to the number of flattened integer elements because read_avail() returns
> the table as a flat array.
> 
> bmp280_write_sampling_frequency(), however, indexes the same table as a
> two-dimensional array and uses num_sampling_freq_avail as the number of
> rows. Convert the flattened element count back to the number of rows
> before iterating over the table.
> 
> Fixes: 10b40ffba2f9 ("iio: pressure: bmp280: Add more tunable config parameters for BMP380")
> Cc: [email protected]
> Signed-off-by: Hui Su <sh_def-9Onoh4P/[email protected]>
> Reviewed-by: Joshua Crofts <[email protected]>

Hi Hui Su

For future reference don't send a new version in reply to an older one. It rapidly looses
all usefulness as the email threads get deeper and more complex.

LGTM Applied to the fixes-togreg branch of iio.git

Note I plan to rebase that once rc1 is out and a pull request will go upstream
sometime after that.

Thanks,

Jonathan

> ---
> Changes in v2:
> - Use plain 2 as the divisor, as suggested by Andy Shevchenko.
> - Add Joshua Crofts' Reviewed-by tag.
> Link: https://lore.kernel.org/lkml/20260805074127.473731-1-sh_def-9Onoh4P/[email protected]/
> 
>  drivers/iio/pressure/bmp280-core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
> index 990340a9b10c..dbe42233c81d 100644
> --- a/drivers/iio/pressure/bmp280-core.c
> +++ b/drivers/iio/pressure/bmp280-core.c
> @@ -836,7 +836,7 @@ static int bmp280_write_sampling_frequency(struct bmp280_data *data,
>  					   int val, int val2)
>  {
>  	const int (*avail)[2] = data->chip_info->sampling_freq_avail;
> -	const int n = data->chip_info->num_sampling_freq_avail;
> +	const int n = data->chip_info->num_sampling_freq_avail / 2;
>  	int ret, prev;
>  	int i;
>