Re: [PATCH] i3c: dw: Annotate struct dw_i3c_xfer with __counted_by

[Gustavo A. R. Silva]

On Fri, Sep 22, 2023 at 10:50:11AM -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 dw_i3c_xfer.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> Cc: Jeremy Kerr <jk@xxxxxxxxxxxxxxxxxxxx>
> Cc: Joel Stanley <joel@xxxxxxxxx>
> Cc: linux-i3c@xxxxxxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>  drivers/i3c/master/dw-i3c-master.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index 9332ae5f6419..ef5751e91cc9 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c
> @@ -233,7 +233,7 @@ struct dw_i3c_xfer {
>  	struct completion comp;
>  	int ret;
>  	unsigned int ncmds;
> -	struct dw_i3c_cmd cmds[];
> +	struct dw_i3c_cmd cmds[] __counted_by(ncmds);
>  };
>  
>  struct dw_i3c_i2c_dev_data {
> -- 
> 2.34.1
> 
>