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=-3.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 385F9C43381 for ; Fri, 22 Feb 2019 22:36:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E47FA206C0 for ; Fri, 22 Feb 2019 22:36:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NnXfS7tz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726099AbfBVWf7 (ORCPT ); Fri, 22 Feb 2019 17:35:59 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:37915 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725774AbfBVWf7 (ORCPT ); Fri, 22 Feb 2019 17:35:59 -0500 Received: by mail-pf1-f195.google.com with SMTP id n125so1728009pfn.5 for ; Fri, 22 Feb 2019 14:35:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=NJMSX6ccWDI2ciRWJrRLVewezGzLllaZkGo9MFRJuNo=; b=NnXfS7tzPo6CLFS2exB9Zo4IzDpBU0GmUx9mNYugnQvwCc6gdcPNGnCsgkCtYioj4m qqxkRnZvNeckHDIDdcm3ICeWPTrC2aH33t9bQKc8dLK9d34te324XcpGlMrPAxD9Ks4T 8qzebb7k6/6GRkNgDgmo47kAwG1BZHXrssNPf23DsB9rNrHt3Vg8vAnfhdEjYpd/wlfk TQLEbSAvrAHInR8DCum0m89crijtc02hyQBxGai/5APRNEMvLvJ/nKEcNkWPkMqadmqP 8IPVen0vtaki5/xlNSfApY0ZarHESHpROQR3VggwjFxlKMKi/v+LwkrvWA5VyAS2Rksk 3vyw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=NJMSX6ccWDI2ciRWJrRLVewezGzLllaZkGo9MFRJuNo=; b=T1aj5CzzN3HtyubYWldSK79B9mkfwV+jy3zFZlE0ZVYw5t+7HnC1UZvQuvgnxToe+L myQ2+tBo21aQMfi+BGNIrWh4vVC8NIr70I7IlPAFSlUgzO02SrTQmXoRr3dCFJWt3MAt 6GFC3cMn791gTE/jU0MBWM1v0IaZd/3+DWtuA3dpkSiQp0NW+Bb5upayvJnhGy8eZiHN b93VDlcbxL786UrOfaNOCjCRKsAqb6Xz+Q8zA+tAvbBsVPr8MKkD6Pqc2j1b0KhBnUNB bLkREDGHq2KoqCoYTxoEFtTt7ykCf0NXEdBj/aQfaIeqQdAGSGFkKiTfVqsY/SYvV7Sh 8jyg== X-Gm-Message-State: AHQUAuaOglJPxT+oK0lrIpRUYdSqQeenQAxJw0CQuUnd5AjlINu8Euu1 IYTQAjJPdUfZgztRFRF0gQE927ik X-Google-Smtp-Source: AHgI3IZCIfQ+IIDiM/UmkbS1L8Yb/Tu275SIqWjIiQSJC5OYPlqlqnq2UCXyyDbFIUfb9HVWXyNZ2g== X-Received: by 2002:a62:6f88:: with SMTP id k130mr6452045pfc.234.1550874958104; Fri, 22 Feb 2019 14:35:58 -0800 (PST) Received: from [172.27.227.214] ([216.129.126.118]) by smtp.googlemail.com with ESMTPSA id 33sm4926887pgs.81.2019.02.22.14.35.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Feb 2019 14:35:57 -0800 (PST) Subject: Re: [PATCH][net-next] ipv6: sanitize RCU usage on fib6_next To: Li RongQing , netdev@vger.kernel.org References: <1550828682-10608-1-git-send-email-lirongqing@baidu.com> From: David Ahern Message-ID: Date: Fri, 22 Feb 2019 17:35:55 -0500 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1550828682-10608-1-git-send-email-lirongqing@baidu.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2/22/19 4:44 AM, Li RongQing wrote: > diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c > index 6613d8dbb0e5..b73d40d68178 100644 > --- a/net/ipv6/ip6_fib.c > +++ b/net/ipv6/ip6_fib.c > @@ -1143,7 +1143,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt, > > atomic_inc(&rt->fib6_ref); > rcu_assign_pointer(rt->fib6_node, fn); > - rt->fib6_next = iter->fib6_next; > + rcu_assign_pointer(rt->fib6_next, iter->fib6_next); > rcu_assign_pointer(*ins, rt); > if (!info->skip_notify) > inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE); > @@ -1761,7 +1761,9 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn, > RT6_TRACE("fib6_del_route\n"); > > /* Unlink it */ > - *rtp = rt->fib6_next; > + *rtp = rcu_dereference_protected(rt->fib6_next, > + lockdep_is_held(&rt->fib6_table->tb6_lock)); > + > rt->fib6_node = NULL; > net->ipv6.rt6_stats->fib_rt_entries--; > net->ipv6.rt6_stats->fib_discarded_routes++; > There are a number of fib6_next references not using rcu api's. Why are you only touching these 2?