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Date:   Sat, 23 Sep 2023 10:30:14 -0600
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Subject: Re: [PATCH] ALSA: hda: Annotate struct hda_conn_list with
 __counted_by
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To:     Kees Cook <keescook@chromium.org>, Jaroslav Kysela <perex@perex.cz>
Cc:     Takashi Iwai <tiwai@suse.com>,
        Cezary Rojewski <cezary.rojewski@intel.com>,
        alsa-devel@alsa-project.org, Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>,
        Kai Vehmanen <kai.vehmanen@linux.intel.com>,
        Jason Montleon <jmontleo@redhat.com>,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        linux-hardening@vger.kernel.org
References: <20230922175042.work.547-kees@kernel.org>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20230922175042.work.547-kees@kernel.org>
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On 9/22/23 11:50, 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 hda_conn_list.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Jaroslav Kysela <perex@perex.cz>
> Cc: Takashi Iwai <tiwai@suse.com>
> Cc: Cezary Rojewski <cezary.rojewski@intel.com>
> Cc: alsa-devel@alsa-project.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   sound/pci/hda/hda_codec.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
> index 33af707a65ab..01718b1fc9a7 100644
> --- a/sound/pci/hda/hda_codec.c
> +++ b/sound/pci/hda/hda_codec.c
> @@ -88,7 +88,7 @@ struct hda_conn_list {
>   	struct list_head list;
>   	int len;
>   	hda_nid_t nid;
> -	hda_nid_t conns[];
> +	hda_nid_t conns[] __counted_by(len);
>   };
>   
>   /* look up the cached results */