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Date:   Fri, 22 Sep 2023 19:57:26 -0600
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Subject: Re: [PATCH 13/14] net: tulip: Annotate struct mediatable with
 __counted_by
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To:     Kees Cook <keescook@chromium.org>, Jakub Kicinski <kuba@kernel.org>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Shaokun Zhang <zhangshaokun@hisilicon.com>,
        netdev@vger.kernel.org, linux-parisc@vger.kernel.org,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        David Ahern <dsahern@kernel.org>,
        Martin KaFai Lau <martin.lau@kernel.org>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Yisen Zhuang <yisen.zhuang@huawei.com>,
        Salil Mehta <salil.mehta@huawei.com>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        Vladimir Oltean <vladimir.oltean@nxp.com>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
        Long Li <longli@microsoft.com>,
        Ajay Sharma <sharmaajay@microsoft.com>,
        Alex Elder <elder@kernel.org>,
        Pravin B Shelar <pshelar@ovn.org>,
        Cong Wang <xiyou.wangcong@gmail.com>,
        Jiri Pirko <jiri@resnulli.us>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, Simon Horman <horms@kernel.org>,
        linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
        linux-rdma@vger.kernel.org, dev@openvswitch.org,
        llvm@lists.linux.dev, linux-hardening@vger.kernel.org
References: <20230922172449.work.906-kees@kernel.org>
 <20230922172858.3822653-13-keescook@chromium.org>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20230922172858.3822653-13-keescook@chromium.org>
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On 9/22/23 11:28, 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 mediatable.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: Shaokun Zhang <zhangshaokun@hisilicon.com>
> Cc: netdev@vger.kernel.org
> Cc: linux-parisc@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   drivers/net/ethernet/dec/tulip/tulip.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/dec/tulip/tulip.h b/drivers/net/ethernet/dec/tulip/tulip.h
> index 0ed598dc7569..bd786dfbc066 100644
> --- a/drivers/net/ethernet/dec/tulip/tulip.h
> +++ b/drivers/net/ethernet/dec/tulip/tulip.h
> @@ -381,7 +381,7 @@ struct mediatable {
>   	unsigned has_reset:6;
>   	u32 csr15dir;
>   	u32 csr15val;		/* 21143 NWay setting. */
> -	struct medialeaf mleaf[];
> +	struct medialeaf mleaf[] __counted_by(leafcount);
>   };
>   
>