Re: [PATCH 10/14] net: openvswitch: Annotate struct dp_meter_instance with __counted_by

[Gustavo A. R. Silva]

On 9/22/23 11:28, 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 dp_meter_instance.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Pravin B Shelar <pshelar@xxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: dev@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>   net/openvswitch/meter.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/openvswitch/meter.h b/net/openvswitch/meter.h
> index 0c33889a8515..013de694221f 100644
> --- a/net/openvswitch/meter.h
> +++ b/net/openvswitch/meter.h
> @@ -45,7 +45,7 @@ struct dp_meter {
>   struct dp_meter_instance {
>   	struct rcu_head rcu;
>   	u32 n_meters;
> -	struct dp_meter __rcu *dp_meters[];
> +	struct dp_meter __rcu *dp_meters[] __counted_by(n_meters);
>   };
>   
>   struct dp_meter_table {