From patchwork Wed Oct 21 02:00:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Di Zhu X-Patchwork-Id: 298721 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2488EC4363D for ; Wed, 21 Oct 2020 02:01:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D597A2242F for ; Wed, 21 Oct 2020 02:01:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439947AbgJUCBm (ORCPT ); Tue, 20 Oct 2020 22:01:42 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:15240 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2439901AbgJUCBm (ORCPT ); Tue, 20 Oct 2020 22:01:42 -0400 Received: from DGGEMS406-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id B067310C8D121468FDF0; Wed, 21 Oct 2020 10:01:39 +0800 (CST) Received: from DESKTOP-9883QJJ.china.huawei.com (10.136.114.155) by DGGEMS406-HUB.china.huawei.com (10.3.19.206) with Microsoft SMTP Server id 14.3.487.0; Wed, 21 Oct 2020 10:01:30 +0800 From: zhudi To: CC: , , , Subject: [PATCH v3] rtnetlink: fix data overflow in rtnl_calcit() Date: Wed, 21 Oct 2020 10:00:53 +0800 Message-ID: <20201021020053.1401-1-zhudi21@huawei.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 X-Originating-IP: [10.136.114.155] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Di Zhu "ip addr show" command execute error when we have a physical network card with a large number of VFs The return value of if_nlmsg_size() in rtnl_calcit() will exceed range of u16 data type when any network cards has a larger number of VFs. rtnl_vfinfo_size() will significant increase needed dump size when the value of num_vfs is larger. Eventually we get a wrong value of min_ifinfo_dump_size because of overflow which decides the memory size needed by netlink dump and netlink_dump() will return -EMSGSIZE because of not enough memory was allocated. So fix it by promoting min_dump_alloc data type to u32 to avoid whole netlink message size overflow and it's also align with the data type of struct netlink_callback{}.min_dump_alloc which is assigned by return value of rtnl_calcit() Signed-off-by: Di Zhu --- /* v1 */ Link: https://lore.kernel.org/netdev/20201019101555.64b9f723/ /* v2 */ - Jakub Kicinski - sorted the variable declarations from longest to shortest. - use size_t for the local variable in rtnl_calcit(). - update commit message /* v3 */ - fix a warning reported by checkpatch.pl --- include/linux/netlink.h | 2 +- net/core/rtnetlink.c | 13 ++++++------- 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 666cd0390699..9f118771e248 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -240,7 +240,7 @@ struct netlink_dump_control { int (*done)(struct netlink_callback *); void *data; struct module *module; - u16 min_dump_alloc; + u32 min_dump_alloc; }; int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 68e0682450c6..7d7223691783 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -3709,13 +3709,13 @@ static int rtnl_dellinkprop(struct sk_buff *skb, struct nlmsghdr *nlh, return rtnl_linkprop(RTM_DELLINKPROP, skb, nlh, extack); } -static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh) +static u32 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); - struct net_device *dev; + size_t min_ifinfo_dump_size = 0; struct nlattr *tb[IFLA_MAX+1]; u32 ext_filter_mask = 0; - u16 min_ifinfo_dump_size = 0; + struct net_device *dev; int hdrlen; /* Same kernel<->userspace interface hack as in rtnl_dump_ifinfo. */ @@ -3735,9 +3735,8 @@ static u16 rtnl_calcit(struct sk_buff *skb, struct nlmsghdr *nlh) */ rcu_read_lock(); for_each_netdev_rcu(net, dev) { - min_ifinfo_dump_size = max_t(u16, min_ifinfo_dump_size, - if_nlmsg_size(dev, - ext_filter_mask)); + min_ifinfo_dump_size = max(min_ifinfo_dump_size, + if_nlmsg_size(dev, ext_filter_mask)); } rcu_read_unlock(); @@ -5494,7 +5493,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) { struct sock *rtnl; rtnl_dumpit_func dumpit; - u16 min_dump_alloc = 0; + u32 min_dump_alloc = 0; link = rtnl_get_link(family, type); if (!link || !link->dumpit) {