On Thu, 17 Oct 2019 12:57:02 +0200, Toke Høiland-Jørgensen wrote:
> Tetsuo pointed out that without an explicit cast, the cost calculation for
> devmap_hash type maps could overflow on 32-bit builds. This adds the
> missing cast.
>
> Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
> Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
> ---
> kernel/bpf/devmap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
> index a0a1153da5ae..e34fac6022eb 100644
> --- a/kernel/bpf/devmap.c
> +++ b/kernel/bpf/devmap.c
> @@ -128,7 +128,7 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
>
> if (!dtab->n_buckets) /* Overflow check */
> return -EINVAL;
> - cost += sizeof(struct hlist_head) * dtab->n_buckets;
> + cost += (u64) sizeof(struct hlist_head) * dtab->n_buckets;
array_size()?
> }
>
> /* if map size is larger than memlock limit, reject it */
