Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.38 as permitted sender) client-ip=23.128.96.38;
From:   Kees Cook <keescook@chromium.org>
To:     Jakub Kicinski <kuba@kernel.org>
Cc:     Kees Cook <keescook@chromium.org>,
        "David S. Miller" <davem@davemloft.net>,
        David Ahern <dsahern@kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        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
Subject: [PATCH 01/14] ipv4: Annotate struct fib_info with __counted_by
Date:   Fri, 22 Sep 2023 10:28:43 -0700
Message-Id: <20230922172858.3822653-1-keescook@chromium.org>
In-Reply-To: <20230922172449.work.906-kees@kernel.org>
References: <20230922172449.work.906-kees@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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 fib_info.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: "David S. Miller" <davem@davemloft.net>
Cc: David Ahern <dsahern@kernel.org>
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>
---
 include/net/ip_fib.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index f0c13864180e..84b0a82c9df4 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -156,7 +156,7 @@ struct fib_info {
 	bool			nh_updated;
 	struct nexthop		*nh;
 	struct rcu_head		rcu;
-	struct fib_nh		fib_nh[];
+	struct fib_nh		fib_nh[] __counted_by(fib_nhs);
 };
 
 
-- 
2.34.1