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=-6.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 C6663C676A8 for ; Thu, 2 Sep 2021 16:41:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8EEB61051 for ; Thu, 2 Sep 2021 16:41:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346359AbhIBQmh (ORCPT ); Thu, 2 Sep 2021 12:42:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234436AbhIBQmg (ORCPT ); Thu, 2 Sep 2021 12:42:36 -0400 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BCC6C061575; Thu, 2 Sep 2021 09:41:38 -0700 (PDT) Received: by mail-pf1-x42c.google.com with SMTP id s29so2098089pfw.5; Thu, 02 Sep 2021 09:41:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=VleJPFXhbF8WRqOsaBBQPjzgoQ2bIzoPQ5j5gsdJ/N4=; b=Cz8RabjQzuMJtB8RAsceldQG5nNB5DV0r/TRNB6W4SHV0C7nj2fupVpn1nAt6PO5F0 jOppsn8OM5ApPZjPQVVAl7sLfx+B8ktsABfi/5YeAX9HMb5XP7e0PI3MfqBAxnJ4PVi0 b9u07dUzUxkDHikaB2qwGUKzV1HSRSGOHGoy3VXOBmgfz2OUBx8nKqkhfGJvEH1Kfue/ IsPXFKGhsyrcSigiBUFGazrK0ySWJhF38AcwqaHjUk87HCr7ghGUjWGCkywXVrezq+VR c/SWbHlMAHii1BbzBCAUMg3Zq7WnFh7jpKvwN4CKmpJru5haf74WfBjqPeEMWzgvITd4 icOA== 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=VleJPFXhbF8WRqOsaBBQPjzgoQ2bIzoPQ5j5gsdJ/N4=; b=INbrfIJpOfz+oxEMYiOma98ZveTxR3N+ioigcPM9HEhxTl/qiQiWl0J51ghXdVkBel 0QlRtrF07NCtLOGahIz/tBvzlpXSvVbzeMm17s8xGIoBgP29lOj3sCAOf5V2O1CZWALb eGdrLNXvtde/m6TANsBFYulpD5WOytR7OfZphwOTnW/SYLG9XEBU2/UueA1TzaGQJMAG tU96Zz0PQSLo6dbYuN6Ol2NRnZ+zbflDZrcEYFK2UnfFIPdMWhTWaAcUUmYch606+zi+ OCcw7zaPOOHkqwCBaH8pjQAoF38EGZ4hjXjevPEbisyL+fQH5UR5+KHAK3sewep9+iy0 YA3g== X-Gm-Message-State: AOAM533zxADhpB/4Vw3ovHydkIINdgXhBm7gDquvwB+rMUHhnikprlqB /1VaF/Khhge+6Ytf2qrx06wGEsAASo4= X-Google-Smtp-Source: ABdhPJxlf/isZnGLzzFeBV8SO4M3XZMMNeLyhuVmrTumSc21EOHaCoUVi6IYD/XkO0BebwVR7FBubw== X-Received: by 2002:a63:34c6:: with SMTP id b189mr3964133pga.122.1630600897300; Thu, 02 Sep 2021 09:41:37 -0700 (PDT) Received: from Davids-MacBook-Pro.local ([8.45.42.119]) by smtp.googlemail.com with ESMTPSA id v8sm2774059pjh.24.2021.09.02.09.41.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 02 Sep 2021 09:41:36 -0700 (PDT) Subject: Re: [PATCH linux-next] ipv4: Fix NULL deference in fnhe_remove_oldest() To: Eric Dumazet , Tim Gardner Cc: netdev , "David S. Miller" , Hideaki YOSHIFUJI , David Ahern , Jakub Kicinski , LKML References: <20210902163205.17164-1-tim.gardner@canonical.com> From: David Ahern Message-ID: <9a1962e2-fa9f-f423-c16d-8ba529a931eb@gmail.com> Date: Thu, 2 Sep 2021 09:41:35 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: 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 9/2/21 9:38 AM, Eric Dumazet wrote: > On Thu, Sep 2, 2021 at 9:32 AM Tim Gardner wrote: >> >> Coverity complains that linux-next commit 67d6d681e15b5 ("ipv4: make >> exception cache less predictible") neglected to check for NULL before >> dereferencing 'oldest'. It appears to be possible to fall through the for >> loop without ever setting 'oldest'. > > Coverity is wrong. > > fnhe_remove_oldest() is only called when there are at least 6 items > in the list. > > There is no way oldest could be NULL, or that oldest_p could contain garbage. > +1