Re: [PATCH] wifi: mt76: Annotate struct mt76_rx_tid with __counted_by

[Kees Cook]

On Fri, Sep 15, 2023 at 01:06:12PM -0700, 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 mt76_rx_tid.

Friendly ping. Can this get picked up by the wifi tree, or should it go
via something else?

Thanks!

-Kees

> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Felix Fietkau <nbd@xxxxxxxx>
> Cc: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
> Cc: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
> Cc: Shayne Chen <shayne.chen@xxxxxxxxxxxx>
> Cc: Sean Wang <sean.wang@xxxxxxxxxxxx>
> Cc: Kalle Valo <kvalo@xxxxxxxxxx>
> Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> Cc: linux-wireless@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-mediatek@xxxxxxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> ---
>  drivers/net/wireless/mediatek/mt76/mt76.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76.h b/drivers/net/wireless/mediatek/mt76/mt76.h
> index e8757865a3d0..03ef617b1527 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76.h
> +++ b/drivers/net/wireless/mediatek/mt76/mt76.h
> @@ -376,7 +376,7 @@ struct mt76_rx_tid {
>  
>  	u8 started:1, stopped:1, timer_pending:1;
>  
> -	struct sk_buff *reorder_buf[];
> +	struct sk_buff *reorder_buf[] __counted_by(size);
>  };
>  
>  #define MT_TX_CB_DMA_DONE		BIT(0)
> -- 
> 2.34.1
> 

-- 
Kees Cook