Re: [PATCH][next] nvdimm/region: Use struct_size() in kzalloc()

[Ira Weiny]

On Fri, Jun 19, 2020 at 12:21:12PM -0500, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes.
> 
> This issue was found with the help of Coccinelle and, audited and fixed
> manually.
> 
> Addresses-KSPP-ID: https://github.com/KSPP/linux/issues/83
> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>

> ---
>  drivers/nvdimm/region_devs.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
> index 4502f9c4708d..8365fb1a9114 100644
> --- a/drivers/nvdimm/region_devs.c
> +++ b/drivers/nvdimm/region_devs.c
> @@ -1063,8 +1063,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
>  		struct nd_blk_region *ndbr;
>  
>  		ndbr_desc = to_blk_region_desc(ndr_desc);
> -		ndbr = kzalloc(sizeof(*ndbr) + sizeof(struct nd_mapping)
> -				* ndr_desc->num_mappings,
> +		ndbr = kzalloc(struct_size(ndbr, nd_region.mapping, ndr_desc->num_mappings),
>  				GFP_KERNEL);
>  		if (ndbr) {
>  			nd_region = &ndbr->nd_region;
> -- 
> 2.27.0
>