Hi,
On Wed, May 01, 2024 at 07:01:22PM +0200, Erick Archer wrote:
> Prepare for the coming implementation by GCC and Clang of the
> __counted_by attribute. Flexible array members annotated with
> __counted_by can have their accesses bounds-checked at run-time via
> CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE
> (for strcpy/memcpy-family functions).
>
> Suggested-by: Kees Cook <[email protected]>
> Signed-off-by: Erick Archer <[email protected]>
> ---
> include/uapi/linux/sctp.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
> index b7d91d4cf0db..836173e73401 100644
> --- a/include/uapi/linux/sctp.h
> +++ b/include/uapi/linux/sctp.h
> @@ -1007,7 +1007,7 @@ enum sctp_sstat_state {
> */
> struct sctp_assoc_ids {
> __u32 gaids_number_of_ids;
> - sctp_assoc_t gaids_assoc_id[];
> + sctp_assoc_t gaids_assoc_id[] __counted_by(gaids_number_of_ids);
Crucially, gaids_number_of_ids is assigned before any accesses to
gaids_assoc_id[] are made.
| ids->gaids_number_of_ids = num;
| num = 0;
| list_for_each_entry(asoc, &(sp->ep->asocs), asocs) {
| ids->gaids_assoc_id[num++] = asoc->assoc_id;
| }
So this looks good to me.
Reviewed-by: Justin Stitt <[email protected]>
> };
>
> /*
> --
> 2.25.1
>
Thanks
Justin
