From mboxrd@z Thu Jan 1 00:00:00 1970 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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 E4192C43381 for ; Tue, 26 Mar 2019 19:46:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AFCAB20823 for ; Tue, 26 Mar 2019 19:46:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732319AbfCZTqw (ORCPT ); Tue, 26 Mar 2019 15:46:52 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:49680 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726278AbfCZTqw (ORCPT ); Tue, 26 Mar 2019 15:46:52 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 2570514C652C3; Tue, 26 Mar 2019 12:46:51 -0700 (PDT) Date: Tue, 26 Mar 2019 12:46:46 -0700 (PDT) Message-Id: <20190326.124646.505432518345625779.davem@davemloft.net> To: mkubecek@suse.cz Cc: netdev@vger.kernel.org, jakub.kicinski@netronome.com, jiri@resnulli.us, andrew@lunn.ch, f.fainelli@gmail.com, linville@tuxdriver.com, stephen@networkplumber.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v5 01/22] rtnetlink: provide permanent hardware address in RTM_NEWLINK From: David Miller In-Reply-To: <16ffb1fbfa8f54de587ac52f4ff95e5034c590b4.1553532199.git.mkubecek@suse.cz> References: <16ffb1fbfa8f54de587ac52f4ff95e5034c590b4.1553532199.git.mkubecek@suse.cz> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Tue, 26 Mar 2019 12:46:51 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michal Kubecek Date: Mon, 25 Mar 2019 18:07:57 +0100 (CET) > @@ -1683,6 +1684,8 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, > nla_put_s32(skb, IFLA_NEW_IFINDEX, new_ifindex) < 0) > goto nla_put_failure; > > + if (nla_put(skb, IFLA_PERM_ADDRESS, dev->addr_len, dev->perm_addr)) > + goto nla_put_failure; > > rcu_read_lock(); > if (rtnl_fill_link_af(skb, dev, ext_filter_mask)) I guess, as Jiri says, we really do have to check if the driver actually set this before pushing the attribute out to userspace. But seriously, you chould just check for dev_addr_len zeros. All zeros is not a valid link address on any link type.