Re: [PATCH 09/14] net: mana: Annotate struct hwc_dma_buf 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 hwc_dma_buf.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Long Li <longli@xxxxxxxxxxxxx>
> Cc: Ajay Sharma <sharmaajay@xxxxxxxxxxxxx>
> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> Cc: Wei Liu <wei.liu@xxxxxxxxxx>
> Cc: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
> Cc: linux-rdma@xxxxxxxxxxxxxxx
> Cc: linux-hyperv@xxxxxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks
--
Gustavo

> ---
>   include/net/mana/hw_channel.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/net/mana/hw_channel.h b/include/net/mana/hw_channel.h
> index 3d3b5c881bc1..158b125692c2 100644
> --- a/include/net/mana/hw_channel.h
> +++ b/include/net/mana/hw_channel.h
> @@ -121,7 +121,7 @@ struct hwc_dma_buf {
>   	u32 gpa_mkey;
>   
>   	u32 num_reqs;
> -	struct hwc_work_request reqs[];
> +	struct hwc_work_request reqs[] __counted_by(num_reqs);
>   };
>   
>   typedef void hwc_rx_event_handler_t(void *ctx, u32 gdma_rxq_id,