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Message-ID: <eba660fc-4284-6793-1598-fd5bdedaca4a@embeddedor.com>
Date:   Sat, 23 Sep 2023 10:37:06 -0600
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Subject: Re: [PATCH] firewire: Annotate struct fw_node with __counted_by
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To:     Kees Cook <keescook@chromium.org>,
        Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc:     linux1394-devel@lists.sourceforge.net,
        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: <20230922175334.work.335-kees@kernel.org>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20230922175334.work.335-kees@kernel.org>
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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 fw_node.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Takashi Sakamoto <o-takashi@sakamocchi.jp>
> Cc: linux1394-devel@lists.sourceforge.net
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   drivers/firewire/core.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
> index 2a05f411328f..95c10f3d2282 100644
> --- a/drivers/firewire/core.h
> +++ b/drivers/firewire/core.h
> @@ -191,7 +191,7 @@ struct fw_node {
>   	/* Upper layer specific data. */
>   	void *data;
>   
> -	struct fw_node *ports[];
> +	struct fw_node *ports[] __counted_by(port_count);
>   };
>   
>   static inline struct fw_node *fw_node_get(struct fw_node *node)