[PATCH] wifi: intersil: hostap: Annotate struct prism2_download_data with __counted_by

[PATCH] wifi: intersil: hostap: Annotate struct prism2_download_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 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
prism2_download_data.

Cc: Kalle Valo <kvalo@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-wireless@vger.kernel.org
Cc: linux-hardening@vger.kernel.org
Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/net/wireless/intersil/hostap/hostap_wlan.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intersil/hostap/hostap_wlan.h b/drivers/net/wireless/intersil/hostap/hostap_wlan.h
index c25cd21d18bd..f71c0545c0be 100644
--- a/drivers/net/wireless/intersil/hostap/hostap_wlan.h
+++ b/drivers/net/wireless/intersil/hostap/hostap_wlan.h
@@ -617,7 +617,7 @@ struct prism2_download_data {
 		u32 addr; /* wlan card address */
 		u32 len;
 		u8 *data; /* allocated data */
-	} data[];
+	} data[] __counted_by(num_areas);
 };
 
 
-- 
2.34.1

Re: [PATCH] wifi: intersil: hostap: Annotate struct prism2_download_data with __counted_by

[Gustavo A. R. Silva]

On 10/6/23 22:19, 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 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
> prism2_download_data.
> 
> Cc: Kalle Valo <kvalo@kernel.org>
> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
> Cc: linux-wireless@vger.kernel.org
> Cc: linux-hardening@vger.kernel.org
> Link: https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci [1]
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks!
--
Gustavo

> ---
>   drivers/net/wireless/intersil/hostap/hostap_wlan.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/intersil/hostap/hostap_wlan.h b/drivers/net/wireless/intersil/hostap/hostap_wlan.h
> index c25cd21d18bd..f71c0545c0be 100644
> --- a/drivers/net/wireless/intersil/hostap/hostap_wlan.h
> +++ b/drivers/net/wireless/intersil/hostap/hostap_wlan.h
> @@ -617,7 +617,7 @@ struct prism2_download_data {
>   		u32 addr; /* wlan card address */
>   		u32 len;
>   		u8 *data; /* allocated data */
> -	} data[];
> +	} data[] __counted_by(num_areas);
>   };
>   
>