[PATCH] i3c/master/mipi-i3c-hci: Annotate struct hci_rings_data with __counted_by

[PATCH] i3c/master/mipi-i3c-hci: Annotate struct hci_rings_data with __counted_by

[Kees Cook]

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 hci_rings_data.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Nicolas Pitre <npitre@baylibre.com>
Cc: Len Baker <len.baker@gmx.com>
Cc: Boris Brezillon <boris.brezillon@collabora.com>
Cc: linux-i3c@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
index 2990ac9eaade..a1ecdfc35641 100644
--- a/drivers/i3c/master/mipi-i3c-hci/dma.c
+++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
@@ -139,7 +139,7 @@ struct hci_rh_data {
 
 struct hci_rings_data {
 	unsigned int total;
-	struct hci_rh_data headers[];
+	struct hci_rh_data headers[] __counted_by(total);
 };
 
 struct hci_dma_dev_ibi_data {
-- 
2.34.1

Re: [PATCH] i3c/master/mipi-i3c-hci: Annotate struct hci_rings_data with __counted_by

[Gustavo A. R. Silva]

On 9/22/23 11:50, 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 hci_rings_data.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Nicolas Pitre <npitre@baylibre.com>
> Cc: Len Baker <len.baker@gmx.com>
> Cc: Boris Brezillon <boris.brezillon@collabora.com>
> Cc: linux-i3c@lists.infradead.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   drivers/i3c/master/mipi-i3c-hci/dma.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c
> index 2990ac9eaade..a1ecdfc35641 100644
> --- a/drivers/i3c/master/mipi-i3c-hci/dma.c
> +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c
> @@ -139,7 +139,7 @@ struct hci_rh_data {
>   
>   struct hci_rings_data {
>   	unsigned int total;
> -	struct hci_rh_data headers[];
> +	struct hci_rh_data headers[] __counted_by(total);
>   };
>   
>   struct hci_dma_dev_ibi_data {

Re: [PATCH] i3c/master/mipi-i3c-hci: Annotate struct hci_rings_data with __counted_by

[Alexandre Belloni]

On Fri, 22 Sep 2023 10:50:19 -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 hci_rings_data.
> 
> [...]

Applied, thanks!

[1/1] i3c/master/mipi-i3c-hci: Annotate struct hci_rings_data with __counted_by
      commit: 751d377f0f7a09d6122de0e2232133524568c52b

Best regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com