Re: [PATCH] ptp: ocp: Add const to bp->attr_group allocation type

[Vadim Fedorenko <vadim.fedorenko@linux.dev>]

On 26/04/2025 07:18, Kees Cook wrote:
> In preparation for making the kmalloc family of allocators type aware,
> we need to make sure that the returned type from the allocation matches
> the type of the variable being assigned. (Before, the allocator would
> always return "void *", which can be implicitly cast to any pointer type.)
> 
> The assigned type is "const struct attribute_group **", but the returned
> type, while technically matching, will be not const qualified. As there is
> no general way to safely add const qualifiers, adjust the allocation type
> to match the assignment.
> 
> Signed-off-by: Kees Cook <kees@kernel.org>
> ---
> Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
> Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
> Cc: Richard Cochran <richardcochran@gmail.com>
> Cc: Andrew Lunn <andrew+netdev@lunn.ch>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: <netdev@vger.kernel.org>
> ---
>   drivers/ptp/ptp_ocp.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
> index faf6e027f89a..ed5968a3ea5a 100644
> --- a/drivers/ptp/ptp_ocp.c
> +++ b/drivers/ptp/ptp_ocp.c
> @@ -2372,7 +2372,7 @@ ptp_ocp_attr_group_add(struct ptp_ocp *bp,
>   		if (attr_tbl[i].cap & bp->fw_cap)
>   			count++;
>   
> -	bp->attr_group = kcalloc(count + 1, sizeof(struct attribute_group *),
> +	bp->attr_group = kcalloc(count + 1, sizeof(*bp->attr_group),
>   				 GFP_KERNEL);
>   	if (!bp->attr_group)
>   		return -ENOMEM;

Thanks,

Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>