Re: [PATCH] iio: gts-helper: Fix memory leaks for i = 1 error path

[Matti Vaittinen <mazziesaccount@gmail.com>]

Thanks a lot Jinjie. I appreciate your fixes!

On 14/10/2024 04:31, Jinjie Ruan wrote:
> If i = 1, and per_time_scales[i] or per_time_gains[i] kcalloc fails in
> iio_gts_build_avail_scale_table(), the err_free_out will fail to enter
> kfree for loop because i-- is 0, and all the per_time_scales[0] and
> per_time_gains[0] will not be freed, which will cause memory leaks.

I guess the loop never frees the memory pointed by the first pointer in 
these arrays. I mean, the freeing is not working as it should even if 
the 'i' was something else but 1.

> 
> Fix it by checking if i >= 0.

The fix seems good to me. So, with a tiny change in commit message:

Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>

> 
> Cc: stable@vger.kernel.org
> Fixes: 38416c28e168 ("iio: light: Add gain-time-scale helpers")
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
>   drivers/iio/industrialio-gts-helper.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/industrialio-gts-helper.c b/drivers/iio/industrialio-gts-helper.c
> index 7326c7949244..5f131bc1a01e 100644
> --- a/drivers/iio/industrialio-gts-helper.c
> +++ b/drivers/iio/industrialio-gts-helper.c
> @@ -315,7 +315,7 @@ static int iio_gts_build_avail_scale_table(struct iio_gts *gts)
>   	return 0;
>   
>   err_free_out:
> -	for (i--; i; i--) {
> +	for (i--; i >= 0; i--) {
>   		kfree(per_time_scales[i]);
>   		kfree(per_time_gains[i]);
>   	}