Re: [PATCH 5/5] cxgb4: Annotate struct smt_data with __counted_by

[Gustavo A. R. Silva]

On 9/29/23 20:11, Kees Cook 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 checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> As found with Coccinelle[1], add __counted_by for struct smt_data.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Raju Rangoju <rajur@xxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks
--
Gustavo

> ---
>   drivers/net/ethernet/chelsio/cxgb4/smt.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/chelsio/cxgb4/smt.h b/drivers/net/ethernet/chelsio/cxgb4/smt.h
> index 541249d78914..109c1dff563a 100644
> --- a/drivers/net/ethernet/chelsio/cxgb4/smt.h
> +++ b/drivers/net/ethernet/chelsio/cxgb4/smt.h
> @@ -66,7 +66,7 @@ struct smt_entry {
>   struct smt_data {
>   	unsigned int smt_size;
>   	rwlock_t lock;
> -	struct smt_entry smtab[];
> +	struct smt_entry smtab[] __counted_by(smt_size);
>   };
>   
>   struct smt_data *t4_init_smt(void);