From nobody Tue Sep 9 07:50:07 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8E989EB64DD for ; Tue, 25 Jul 2023 02:33:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230233AbjGYCd5 (ORCPT ); Mon, 24 Jul 2023 22:33:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230216AbjGYCdy (ORCPT ); Mon, 24 Jul 2023 22:33:54 -0400 Received: from zg8tmtyylji0my4xnjqumte4.icoremail.net (zg8tmtyylji0my4xnjqumte4.icoremail.net [162.243.164.118]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 29C711737; Mon, 24 Jul 2023 19:33:50 -0700 (PDT) Received: from localhost.localdomain (unknown [36.24.99.225]) by mail-app3 (Coremail) with SMTP id cC_KCgBXPot7NL9k9rWkCw--.5856S4; Tue, 25 Jul 2023 10:33:31 +0800 (CST) From: Lin Ma To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ast@kernel.org, martin.lau@kernel.org, yhs@fb.com, void@manifault.com, andrii@kernel.org, houtao1@huawei.com, inwardvessel@gmail.com, linma@zju.edu.cn, kuniyu@amazon.com, songliubraving@fb.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH v2] bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing Date: Tue, 25 Jul 2023 10:33:30 +0800 Message-Id: <20230725023330.422856-1-linma@zju.edu.cn> X-Mailer: git-send-email 2.17.1 X-CM-TRANSID: cC_KCgBXPot7NL9k9rWkCw--.5856S4 X-Coremail-Antispam: 1UD129KBjvJXoW7uF4kXFy8JryDuw13KFykZrb_yoW8GFy7pa s7Gr9xKr9rJrWfCFn7Jrsxua4UCw4UXFy3WFs8Zw4fZw4qqa43Gry3GF1Fqw15ArWrW3Wa yr1YgFy3ur9rZaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvG14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26F4U JVW0owA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AKxVW0oV Cq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0 I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r 4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8vx2IErcIFxwACI402YVCY1x02628v n2kIc2xKxwCY02Avz4vE14v_Gr1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr 0_Gr1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY 17CE14v26r4a6rW5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcV C0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY 6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa 73UjIFyTuYvjfUOTmhUUUUU X-CM-SenderInfo: qtrwiiyqvtljo62m3hxhgxhubq/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The nla_for_each_nested parsing in function bpf_sk_storage_diag_alloc does not check the length of the nested attribute. This can lead to an out-of-attribute read and allow a malformed nlattr (e.g., length 0) to be viewed as a 4 byte integer. This patch adds an additional check when the nlattr is getting counted. This makes sure the latter nla_get_u32 can access the attributes with the correct length. Fixes: 1ed4d92458a9 ("bpf: INET_DIAG support in bpf_sk_storage") Suggested-by: Jakub Kicinski Signed-off-by: Lin Ma Reviewed-by: Jakub Kicinski --- V1 -> V2: moves the check to the counting loop as Jakub suggested, alters the commit message accordingly. net/core/bpf_sk_storage.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index d4172534dfa8..cca7594be92e 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -496,8 +496,11 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla_stg= s) return ERR_PTR(-EPERM); =20 nla_for_each_nested(nla, nla_stgs, rem) { - if (nla_type(nla) =3D=3D SK_DIAG_BPF_STORAGE_REQ_MAP_FD) + if (nla_type(nla) =3D=3D SK_DIAG_BPF_STORAGE_REQ_MAP_FD) { + if (nla_len(nla) !=3D sizeof(u32)) + return ERR_PTR(-EINVAL); nr_maps++; + } } =20 diag =3D kzalloc(struct_size(diag, maps, nr_maps), GFP_KERNEL); --=20 2.17.1