media: allegro: Annotate struct mcu_msg_push_buffers_internal with __counted_by

Message ID 20230922174935.work.699-kees@kernel.org
State New
Headers
Series media: allegro: Annotate struct mcu_msg_push_buffers_internal with __counted_by |

Commit Message

Kees Cook Sept. 22, 2023, 5:49 p.m. UTC
  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 mcu_msg_push_buffers_internal.

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

Cc: Michael Tretter <m.tretter@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-media@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/media/platform/allegro-dvt/allegro-mail.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
  

Comments

Gustavo A. R. Silva Sept. 23, 2023, 4:25 p.m. UTC | #1
On 9/22/23 11:49, 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 mcu_msg_push_buffers_internal.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Michael Tretter <m.tretter@pengutronix.de>
> Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: linux-media@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
  
Kees Cook Oct. 6, 2023, 8:27 p.m. UTC | #2
On Fri, 22 Sep 2023 10:49:36 -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 mcu_msg_push_buffers_internal.
> 
> [...]

Since this is a trivial change and it's been 2 week without further
discussion, I'll snag this patch.

Applied to for-next/hardening, thanks!

[1/1] media: allegro: Annotate struct mcu_msg_push_buffers_internal with __counted_by
      https://git.kernel.org/kees/c/63eed8dcdf49

Take care,
  

Patch

diff --git a/drivers/media/platform/allegro-dvt/allegro-mail.h b/drivers/media/platform/allegro-dvt/allegro-mail.h
index a5686058d754..c0c9013f1aab 100644
--- a/drivers/media/platform/allegro-dvt/allegro-mail.h
+++ b/drivers/media/platform/allegro-dvt/allegro-mail.h
@@ -184,7 +184,7 @@  struct mcu_msg_push_buffers_internal {
 	struct mcu_msg_header header;
 	u32 channel_id;
 	size_t num_buffers;
-	struct mcu_msg_push_buffers_internal_buffer buffer[];
+	struct mcu_msg_push_buffers_internal_buffer buffer[] __counted_by(num_buffers);
 };
 
 struct mcu_msg_put_stream_buffer {