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From:   Yuntao Wang <ytcoode@gmail.com>
To:     Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Andrii Nakryiko <andrii@kernel.org>
Cc:     Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
        Yonghong Song <yhs@fb.com>,
        John Fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>, netdev@vger.kernel.org,
        bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
        Yuntao Wang <ytcoode@gmail.com>
Subject: [PATCH bpf-next] bpf: Simplify check in btf_parse_hdr()
Date:   Sun, 20 Mar 2022 15:52:40 +0800
Message-Id: <20220320075240.1001728-1-ytcoode@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Replace offsetof(hdr_len) + sizeof(hdr_len) with offsetofend(hdr_len) to
simplify the check for correctness of btf_data_size in btf_parse_hdr()

Signed-off-by: Yuntao Wang <ytcoode@gmail.com>
---
 kernel/bpf/btf.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 6d9e711cb5d4..97fd853db16b 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4480,8 +4480,7 @@ static int btf_parse_hdr(struct btf_verifier_env *env)
 	btf = env->btf;
 	btf_data_size = btf->data_size;
 
-	if (btf_data_size <
-	    offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) {
+	if (btf_data_size < offsetofend(struct btf_header, hdr_len)) {
 		btf_verifier_log(env, "hdr_len not found");
 		return -EINVAL;
 	}
-- 
2.35.1