Re: [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by

[Linus Walleij <linus.walleij@xxxxxxxxxx>]

On Fri, Sep 22, 2023 at 7:52 PM Kees Cook <keescook@xxxxxxxxxxxx> 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 linereq.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Cc: Bartosz Golaszewski <brgl@xxxxxxxx>
> Cc: Andy Shevchenko <andy@xxxxxxxxxx>
> Cc: linux-gpio@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

That's neat!
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Yours,
Linus Walleij