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 tsens_priv.

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

Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
Cc: Amit Kucheria <amitk@kernel.org>
Cc: Thara Gopinath <thara.gopinath@gmail.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/thermal/qcom/tsens.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
index 2805de1c6827..cb637fa289ca 100644
--- a/drivers/thermal/qcom/tsens.h
+++ b/drivers/thermal/qcom/tsens.h
@@ -585,7 +585,7 @@ struct tsens_priv {
 	struct dentry			*debug_root;
 	struct dentry			*debug;
 
-	struct tsens_sensor		sensor[];
+	struct tsens_sensor		sensor[] __counted_by(num_sensors);
 };
 
 /**
-- 
2.34.1

On Fri, 22 Sep 2023 10:53:41 -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 tsens_priv.
> 
> [...]

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] drivers: thermal: tsens: Annotate struct tsens_priv with __counted_by
      https://git.kernel.org/kees/c/aa0a14629c2d

Take care,

-- 
Kees Cook

On 9/22/23 11:53, 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 tsens_priv.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Andy Gross <agross@kernel.org>
> Cc: Bjorn Andersson <andersson@kernel.org>
> Cc: Konrad Dybcio <konrad.dybcio@linaro.org>
> Cc: Amit Kucheria <amitk@kernel.org>
> Cc: Thara Gopinath <thara.gopinath@gmail.com>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: linux-arm-msm@vger.kernel.org
> Cc: linux-pm@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   drivers/thermal/qcom/tsens.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/thermal/qcom/tsens.h b/drivers/thermal/qcom/tsens.h
> index 2805de1c6827..cb637fa289ca 100644
> --- a/drivers/thermal/qcom/tsens.h
> +++ b/drivers/thermal/qcom/tsens.h
> @@ -585,7 +585,7 @@ struct tsens_priv {
>   	struct dentry			*debug_root;
>   	struct dentry			*debug;
>   
> -	struct tsens_sensor		sensor[];
> +	struct tsens_sensor		sensor[] __counted_by(num_sensors);
>   };
>   
>   /**