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=-9.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 8F350C432BE for ; Mon, 2 Aug 2021 18:04:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7221861050 for ; Mon, 2 Aug 2021 18:04:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229988AbhHBSEP (ORCPT ); Mon, 2 Aug 2021 14:04:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229537AbhHBSEO (ORCPT ); Mon, 2 Aug 2021 14:04:14 -0400 Received: from mail-oi1-x234.google.com (mail-oi1-x234.google.com [IPv6:2607:f8b0:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D174FC06175F for ; Mon, 2 Aug 2021 11:04:04 -0700 (PDT) Received: by mail-oi1-x234.google.com with SMTP id o185so24986572oih.13 for ; Mon, 02 Aug 2021 11:04:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=ub3iNB9nu3tAdrRcFhLthYkZMNu6YCAg1v/gDWW65is=; b=M3dmhjpAiRH2+7OT+1Bz2opmZfitPS8r6XDKxv4TJGhI45F4r6HuzYBzQJjB8vMznn ojLSoQ+FDZyaNuDlP+Im6A/FXzKYIxt9bHvjkAMZSwWZ5o8oDuQMCxepsuzr0S3QTG5x 573PIeXJJfODTPiVA4jtx9lC5T2jCDrOikasrXbWyEwDHMNiKIaSgACp3vJ1VocLemuI iudeT5vwVmxv0BqzQro/r0wOR9EyvjxUgz0QEuO0D1LbDSERnPNMRS2LWpapMrGrlkB0 pGpkOX3Z8+gY1lppFltKtnkpfQTRKVN5mIuZwNNQow8qY1V8CTOSX+NzhVE2BzGOuegR F2UA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ub3iNB9nu3tAdrRcFhLthYkZMNu6YCAg1v/gDWW65is=; b=CACZy2EPNTEjQc8WVSsqw4N6taU7o388IlLdeQ17OJ5IIZ+4U9Ed4yPwt+LtiOQeAm 6Hle4KY8ZPR4CQfTWBlCJoiGmxG+EjfnFjcWSSVWgDhWzpp6Cw/vMJ2GSoTQEuz3sTR/ 1dULw2wJhvXJebXEkU1aogMWTGNRP0B8ftdxt68PIwEl3v89AWx/vE4H2y+TIipniPI6 uHLZKX+VimAxQIQpunFS02xuL9vRFwiAAIgiwnSYUp9KS1umK97NNtlDqOIZIR4gtVfi Bcag+xDqgv9mg2PGGpGjX1iLa5NL24skq6NM6qy0eYwvNA09/YWTVe9WNzNue6RZmAjA iJLQ== X-Gm-Message-State: AOAM532IxVXl2gJPYlzv44TziCjC5z+14qHMpusD7rOBaBjp+rzdL5u3 duHEnV/21J3Nv5To9pfxMNU= X-Google-Smtp-Source: ABdhPJzYdDKz5E0ryiA7GksamLuu6rjuxlI0PhsIE09DmgpgyUPE17tP226svioERasQdlo/R/brSg== X-Received: by 2002:a05:6808:8e5:: with SMTP id d5mr11376281oic.51.1627927444231; Mon, 02 Aug 2021 11:04:04 -0700 (PDT) Received: from Davids-MacBook-Pro.local ([8.48.134.27]) by smtp.googlemail.com with ESMTPSA id c11sm1813987oot.25.2021.08.02.11.04.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 02 Aug 2021 11:04:03 -0700 (PDT) Subject: Re: [PATCH net-next] ipv4: Fix refcount warning for new fib_info To: Matthieu Baerts , David Ahern Cc: ciorneiioana@gmail.com, Yajun Deng , netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org References: <20210802160221.27263-1-dsahern@kernel.org> <332304e5-7ef7-d977-a777-fd513d6e7d26@tessares.net> From: David Ahern Message-ID: <21559c43-d034-2352-efe4-b366d659da7c@gmail.com> Date: Mon, 2 Aug 2021 12:04:01 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <332304e5-7ef7-d977-a777-fd513d6e7d26@tessares.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 8/2/21 11:58 AM, Matthieu Baerts wrote: > Hi David, > > On 02/08/2021 18:02, David Ahern wrote: >> Ioana reported a refcount warning when booting over NFS: >> >> [ 5.042532] ------------[ cut here ]------------ >> [ 5.047184] refcount_t: addition on 0; use-after-free. >> [ 5.052324] WARNING: CPU: 7 PID: 1 at lib/refcount.c:25 refcount_warn_saturate+0xa4/0x150 >> ... >> [ 5.167201] Call trace: >> [ 5.169635] refcount_warn_saturate+0xa4/0x150 >> [ 5.174067] fib_create_info+0xc00/0xc90 >> [ 5.177982] fib_table_insert+0x8c/0x620 >> [ 5.181893] fib_magic.isra.0+0x110/0x11c >> [ 5.185891] fib_add_ifaddr+0xb8/0x190 >> [ 5.189629] fib_inetaddr_event+0x8c/0x140 >> >> fib_treeref needs to be set after kzalloc. The old code had a ++ which >> led to the confusion when the int was replaced by a refcount_t. > > Thank you for the patch! > > My CI was also complaining of not being able to run kernel selftests [1]. > Your patch fixes the issue, thanks! > > Tested-by: Matthieu Baerts > Given how easily it is to trigger the warning, I get the impression the original was an untested patch.