Re: [PATCH v2 2/2] ACPI: NFIT: use struct_size() helper

[Ira Weiny <ira.weiny@intel.com>]

Yu Liao wrote:
> Make use of the struct_size() helper instead of an open-coded version,
> in order to avoid any potential type mistakes or integer overflows that,
> in the worst scenario, could lead to heap overflows.
> 
> Signed-off-by: Yu Liao <liaoyu15@huawei.com>
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>

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

> ---
>  drivers/acpi/nfit/core.c | 10 ++++------
>  1 file changed, 4 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
> index 305f590c54a8..2f7217600307 100644
> --- a/drivers/acpi/nfit/core.c
> +++ b/drivers/acpi/nfit/core.c
> @@ -712,8 +712,7 @@ static bool add_spa(struct acpi_nfit_desc *acpi_desc,
>  		}
>  	}
>  
> -	nfit_spa = devm_kzalloc(dev, sizeof(*nfit_spa) + sizeof_spa(spa),
> -			GFP_KERNEL);
> +	nfit_spa = devm_kzalloc(dev, struct_size(nfit_spa, spa, 1), GFP_KERNEL);
>  	if (!nfit_spa)
>  		return false;
>  	INIT_LIST_HEAD(&nfit_spa->list);
> @@ -741,7 +740,7 @@ static bool add_memdev(struct acpi_nfit_desc *acpi_desc,
>  			return true;
>  		}
>  
> -	nfit_memdev = devm_kzalloc(dev, sizeof(*nfit_memdev) + sizeof(*memdev),
> +	nfit_memdev = devm_kzalloc(dev, struct_size(nfit_memdev, memdev, 1),
>  			GFP_KERNEL);
>  	if (!nfit_memdev)
>  		return false;
> @@ -812,8 +811,7 @@ static bool add_dcr(struct acpi_nfit_desc *acpi_desc,
>  			return true;
>  		}
>  
> -	nfit_dcr = devm_kzalloc(dev, sizeof(*nfit_dcr) + sizeof(*dcr),
> -			GFP_KERNEL);
> +	nfit_dcr = devm_kzalloc(dev, struct_size(nfit_dcr, dcr, 1), GFP_KERNEL);
>  	if (!nfit_dcr)
>  		return false;
>  	INIT_LIST_HEAD(&nfit_dcr->list);
> @@ -855,7 +853,7 @@ static size_t sizeof_idt(struct acpi_nfit_interleave *idt)
>  {
>  	if (idt->header.length < sizeof(*idt))
>  		return 0;
> -	return sizeof(*idt) + sizeof(u32) * idt->line_count;
> +	return struct_size(idt, line_offset, idt->line_count);
>  }
>  
>  static bool add_idt(struct acpi_nfit_desc *acpi_desc,
> -- 
> 2.25.1
>