Re: [PATCH v3 2/2] igb: Proactively round up to kmalloc bucket size

From: Kees Cook
Date: Fri Oct 28 2022 - 23:17:57 EST


On Tue, Oct 18, 2022 at 02:25:25AM -0700, Kees Cook wrote:
> In preparation for removing the "silently change allocation size"
> users of ksize(), explicitly round up all q_vector allocations so that
> allocations can be correctly compared to ksize().
>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Hi! Any feedback on this part of the patch pair?

> ---
> drivers/net/ethernet/intel/igb/igb_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
> index 6256855d0f62..7a3a41dc0276 100644
> --- a/drivers/net/ethernet/intel/igb/igb_main.c
> +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> @@ -1195,7 +1195,7 @@ static int igb_alloc_q_vector(struct igb_adapter *adapter,
> return -ENOMEM;
>
> ring_count = txr_count + rxr_count;
> - size = struct_size(q_vector, ring, ring_count);
> + size = kmalloc_size_roundup(struct_size(q_vector, ring, ring_count));
>
> /* allocate q_vector and rings */
> q_vector = adapter->q_vector[v_idx];

Thanks! :)

-Kees

--
Kees Cook