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Message-ID: <17cda7da-a70f-8d0d-4224-c82b0ddc4364@embeddedor.com>
Date:   Sat, 23 Sep 2023 10:35:07 -0600
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Subject: Re: [PATCH] libata: Annotate struct ata_cpr_log with __counted_by
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To:     Kees Cook <keescook@chromium.org>,
        Damien Le Moal <dlemoal@kernel.org>
Cc:     linux-ide@vger.kernel.org, Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev, linux-hardening@vger.kernel.org
References: <20230922175210.work.239-kees@kernel.org>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20230922175210.work.239-kees@kernel.org>
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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 ata_cpr_log.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Damien Le Moal <dlemoal@kernel.org>
> Cc: linux-ide@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   include/linux/libata.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index 3c17a5053f00..f91e8e7f1c00 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -656,7 +656,7 @@ struct ata_cpr {
>   
>   struct ata_cpr_log {
>   	u8			nr_cpr;
> -	struct ata_cpr		cpr[];
> +	struct ata_cpr		cpr[] __counted_by(nr_cpr);
>   };
>   
>   struct ata_device {