Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:4 as permitted sender) client-ip=2620:137:e000::3:4;
Message-ID: <68545f64-067f-4109-8e63-dd00d92cbe09@embeddedor.com>
Date:   Fri, 22 Sep 2023 19:51:22 -0600
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.1
Subject: Re: [PATCH 03/14] ipv6: Annotate struct ip6_sf_socklist with
 __counted_by
Content-Language: en-US
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>, netdev@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>,
        Shaokun Zhang <zhangshaokun@hisilicon.com>,
        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,
        linux-parisc@vger.kernel.org, llvm@lists.linux.dev,
        linux-hardening@vger.kernel.org
References: <20230922172449.work.906-kees@kernel.org>
 <20230922172858.3822653-3-keescook@chromium.org>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <20230922172858.3822653-3-keescook@chromium.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


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 ip6_sf_socklist.
> 
> [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: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
-- 
Gustavo

> ---
>   include/net/if_inet6.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
> index c8490729b4ae..3e454c4d7ba6 100644
> --- a/include/net/if_inet6.h
> +++ b/include/net/if_inet6.h
> @@ -89,7 +89,7 @@ struct ip6_sf_socklist {
>   	unsigned int		sl_max;
>   	unsigned int		sl_count;
>   	struct rcu_head		rcu;
> -	struct in6_addr		sl_addr[];
> +	struct in6_addr		sl_addr[] __counted_by(sl_max);
>   };
>   
>   #define IP6_SFBLOCK	10	/* allocate this many at once */