Re: [PATCH] staging: rtl8192e: Annotate struct rtllib_txb with __counted_by

[Philipp Hortmann]

On 8/17/23 22:45, 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 rtllib_txb.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Philipp Hortmann <philipp.g.hortmann@xxxxxxxxx>
> Cc: linux-staging@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> ---
>   drivers/staging/rtl8192e/rtllib.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/staging/rtl8192e/rtllib.h b/drivers/staging/rtl8192e/rtllib.h
> index c5a692dfcd17..543d8671281d 100644
> --- a/drivers/staging/rtl8192e/rtllib.h
> +++ b/drivers/staging/rtl8192e/rtllib.h
> @@ -818,7 +818,7 @@ struct rtllib_txb {
>   	u16 reserved;
>   	__le16 frag_size;
>   	__le16 payload_size;
> -	struct sk_buff *fragments[];
> +	struct sk_buff *fragments[] __counted_by(nr_frags);
>   };
>   
>   #define MAX_SUBFRAME_COUNT		  64

Tested-by: Philipp Hortmann <philipp.g.hortmann@xxxxxxxxx>