* Re: [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by
2023-09-22 17:52 [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by Kees Cook
@ 2023-09-23 16:34 ` Gustavo A. R. Silva
2023-09-24 0:15 ` Linus Walleij
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Gustavo A. R. Silva @ 2023-09-23 16:34 UTC (permalink / raw)
To: Kees Cook, Linus Walleij
Cc: Bartosz Golaszewski, Andy Shevchenko, linux-gpio,
Nathan Chancellor, Nick Desaulniers, Tom Rix, linux-kernel, llvm,
linux-hardening
On 9/22/23 11:52, 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 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@linaro.org>
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Andy Shevchenko <andy@kernel.org>
> Cc: linux-gpio@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks
--
Gustavo
> ---
> drivers/gpio/gpiolib-cdev.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
> index e39d344feb28..31fc71a612c2 100644
> --- a/drivers/gpio/gpiolib-cdev.c
> +++ b/drivers/gpio/gpiolib-cdev.c
> @@ -572,7 +572,7 @@ struct linereq {
> DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event);
> atomic_t seqno;
> struct mutex config_mutex;
> - struct line lines[];
> + struct line lines[] __counted_by(num_lines);
> };
>
> #define GPIO_V2_LINE_BIAS_FLAGS \
> @@ -1656,6 +1656,7 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
> lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL);
> if (!lr)
> return -ENOMEM;
> + lr->num_lines = ulr.num_lines;
>
> lr->gdev = gpio_device_get(gdev);
>
> @@ -1684,7 +1685,6 @@ static int linereq_create(struct gpio_device *gdev, void __user *ip)
> lr->event_buffer_size = GPIO_V2_LINES_MAX * 16;
>
> atomic_set(&lr->seqno, 0);
> - lr->num_lines = ulr.num_lines;
>
> /* Request each GPIO */
> for (i = 0; i < ulr.num_lines; i++) {
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by
2023-09-22 17:52 [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by Kees Cook
2023-09-23 16:34 ` Gustavo A. R. Silva
@ 2023-09-24 0:15 ` Linus Walleij
2023-09-25 6:53 ` Andy Shevchenko
2023-09-25 7:42 ` Bartosz Golaszewski
3 siblings, 0 replies; 5+ messages in thread
From: Linus Walleij @ 2023-09-24 0:15 UTC (permalink / raw)
To: Kees Cook
Cc: Bartosz Golaszewski, Andy Shevchenko, linux-gpio,
Nathan Chancellor, Nick Desaulniers, Tom Rix, linux-kernel, llvm,
linux-hardening
On Fri, Sep 22, 2023 at 7:52 PM Kees Cook <keescook@chromium.org> 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@linaro.org>
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Andy Shevchenko <andy@kernel.org>
> Cc: linux-gpio@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
That's neat!
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by
2023-09-22 17:52 [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by Kees Cook
2023-09-23 16:34 ` Gustavo A. R. Silva
2023-09-24 0:15 ` Linus Walleij
@ 2023-09-25 6:53 ` Andy Shevchenko
2023-09-25 7:42 ` Bartosz Golaszewski
3 siblings, 0 replies; 5+ messages in thread
From: Andy Shevchenko @ 2023-09-25 6:53 UTC (permalink / raw)
To: Kees Cook
Cc: Linus Walleij, Bartosz Golaszewski, linux-gpio, Nathan Chancellor,
Nick Desaulniers, Tom Rix, linux-kernel, llvm, linux-hardening
On Fri, Sep 22, 2023 at 10:52:03AM -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 linereq.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
Ah, hadn't taken into account in my patch, so, Bart, feel free to ignore mine
and apply this one.
Reviewed-by: Andy Shevchenko <andy@kernel.org>
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by
2023-09-22 17:52 [PATCH] gpiolib: cdev: Annotate struct linereq with __counted_by Kees Cook
` (2 preceding siblings ...)
2023-09-25 6:53 ` Andy Shevchenko
@ 2023-09-25 7:42 ` Bartosz Golaszewski
3 siblings, 0 replies; 5+ messages in thread
From: Bartosz Golaszewski @ 2023-09-25 7:42 UTC (permalink / raw)
To: Kees Cook
Cc: Linus Walleij, Andy Shevchenko, linux-gpio, Nathan Chancellor,
Nick Desaulniers, Tom Rix, linux-kernel, llvm, linux-hardening
On Fri, Sep 22, 2023 at 7:52 PM Kees Cook <keescook@chromium.org> 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@linaro.org>
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Andy Shevchenko <andy@kernel.org>
> Cc: linux-gpio@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
Applied, thanks!
Bart
^ permalink raw reply [flat|nested] 5+ messages in thread