From nobody Mon Feb 9 03:46:45 2026 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 9AEA5EB64DD for ; Tue, 25 Jul 2023 05:57:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231905AbjGYF5m (ORCPT ); Tue, 25 Jul 2023 01:57:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229780AbjGYF5j (ORCPT ); Tue, 25 Jul 2023 01:57:39 -0400 X-Greylist: delayed 554 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 24 Jul 2023 22:57:35 PDT Received: from sgoci-sdnproxy-4.icoremail.net (sgoci-sdnproxy-4.icoremail.net [129.150.39.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9DF34E69; Mon, 24 Jul 2023 22:57:35 -0700 (PDT) Received: from localhost.localdomain (unknown [183.128.129.228]) by mail-app2 (Coremail) with SMTP id by_KCgD3TRg0ZL9kpBKFCg--.13835S4; Tue, 25 Jul 2023 13:57:08 +0800 (CST) From: Lin Ma To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, razor@blackwall.org, idosch@nvidia.com, lucien.xin@gmail.com, liuhangbin@gmail.com, edwin.peer@broadcom.com, jiri@resnulli.us, md.fahad.iqbal.polash@intel.com, anirudh.venkataramanan@intel.com, jeffrey.t.kirsher@intel.com, neerav.parikh@intel.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Lin Ma Subject: [PATCH v2] rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length Date: Tue, 25 Jul 2023 13:57:06 +0800 Message-Id: <20230725055706.498774-1-linma@zju.edu.cn> X-Mailer: git-send-email 2.17.1 X-CM-TRANSID: by_KCgD3TRg0ZL9kpBKFCg--.13835S4 X-Coremail-Antispam: 1UD129KBjvJXoW7Zr4rAw15KF4Dtr45WrWkXrb_yoW8uF4fp3 W8Ka47JF4DXrn2vFsrZF17Xa4fZFZ3KFW5Gr42ywn2yr1jqFyUCryqkrn09ry3CFsaqa45 tr4DCFyYvw1DWFDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvK14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E 2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJV W8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I648v4I1lFIxGxcIEc7CjxVA2 Y2ka0xkIwI1lc2xSY4AK67AK6r4rMxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r 1j6r4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CE b7AF67AKxVW8ZVWrXwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0x vE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAI cVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBIdaVFxh VjvjDU0xZFpf9x0JU9189UUUUU= 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" There are totally 9 ndo_bridge_setlink handlers in the current kernel, which are 1) bnxt_bridge_setlink, 2) be_ndo_bridge_setlink 3) i40e_ndo_bridge_setlink 4) ice_bridge_setlink 5) ixgbe_ndo_bridge_setlink 6) mlx5e_bridge_setlink 7) nfp_net_bridge_setlink 8) qeth_l2_bridge_setlink 9) br_setlink. By investigating the code, we find that 1-7 parse and use nlattr IFLA_BRIDGE_MODE but 3 and 4 forget to do the nla_len check. This can lead to an out-of-attribute read and allow a malformed nlattr (e.g., length 0) to be viewed as a 2 byte integer. To avoid such issues, also for other ndo_bridge_setlink handlers in the future. This patch adds the nla_len check in rtnl_bridge_setlink and does an early error return if length mismatches. To make it works, the break is removed from the parsing for IFLA_BRIDGE_FLAGS to make sure this nla_for_each_nested iterates every attribute. Fixes: b1edc14a3fbf ("ice: Implement ice_bridge_getlink and ice_bridge_setl= ink") Fixes: 51616018dd1b ("i40e: Add support for getlink, setlink ndo ops") Suggested-by: Jakub Kicinski Signed-off-by: Lin Ma Acked-by: Nikolay Aleksandrov --- V1 -> V2: removes the break in parsing for IFLA_BRIDGE_FLAGS suggested by Hangbin Liu net/core/rtnetlink.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 3ad4e030846d..aef25aa5cf1d 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -5140,13 +5140,17 @@ static int rtnl_bridge_setlink(struct sk_buff *skb,= struct nlmsghdr *nlh, br_spec =3D nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC); if (br_spec) { nla_for_each_nested(attr, br_spec, rem) { - if (nla_type(attr) =3D=3D IFLA_BRIDGE_FLAGS) { + if (nla_type(attr) =3D=3D IFLA_BRIDGE_FLAGS && !have_flags) { if (nla_len(attr) < sizeof(flags)) return -EINVAL; =20 have_flags =3D true; flags =3D nla_get_u16(attr); - break; + } + + if (nla_type(attr) =3D=3D IFLA_BRIDGE_MODE) { + if (nla_len(attr) < sizeof(u16)) + return -EINVAL; } } } --=20 2.17.1