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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 26897C3279B for ; Fri, 6 Jul 2018 14:48:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF0D023FFF for ; Fri, 6 Jul 2018 14:48:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="n5EndWMi" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF0D023FFF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933157AbeGFOsn (ORCPT ); Fri, 6 Jul 2018 10:48:43 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:38906 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753915AbeGFOsm (ORCPT ); Fri, 6 Jul 2018 10:48:42 -0400 Received: by mail-pf0-f195.google.com with SMTP id j17-v6so8651230pfn.5; Fri, 06 Jul 2018 07:48:41 -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=+/9KVHOzBAXJiD5uqvSDJJ8/Fg6+k+QIJneve1jOLJE=; b=n5EndWMiDCkLsi1yVqTvv4GNCmLrl+5q4bf/ktXWzSA4GaqBGxPVTTDl6f62bR6frR UvSobEia0QOLzr1oSqwVdt7AFVUqc+j/MVyP/ym8z4DuXYrC/9wqXAlqrKNpCMWBBG+s 46o64C29KUtrZy/QIJxYO3ikZygjd8cwT+C/WxxYvNKSThGbT36alkrbJHKdQMVg3mMy hSpiPV4UAJg85Vmrbop9XRN6HFwDFCuXdLgO0kt277qCRaMzydjAYvrZT9FxWhbEm8H/ icfnkNE6vPU056D2vo0yIC+w007NgeijdRRh19P5fvMeD/Ue66w39PLgMVaDRHgXhiOL lgzg== 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=+/9KVHOzBAXJiD5uqvSDJJ8/Fg6+k+QIJneve1jOLJE=; b=sddfpFSvxIuOtDe7c5IPefKcwGV5CEfeYx7sGHBRMmzMpa05lDiWO2j8SiATs22vR8 ohMS0Oe649NbvLtXFdBtm2lWJYzkBJbmUlbF7u0/crOIxvhVBgzszcJfHD7KX+lS+dW6 jq69MZsqhhxmY41r1ApPlXZwci8Ca4AtBEaQs2V50TcDZFWhjpipepZ7W8gVWQp9AHOP 1kf4ugnRpL4MU6I64Pbbzbv//viAHpA68lSayzzITC+ywrw69XDDhLwopMIcdiH3NXjL cy4w/fQhYFJe2EgfIfFhjygTl8Cdn0T5GebB1PcT3qonONzVRZUQc+2lYKktncf6QW7j Qz1w== X-Gm-Message-State: APt69E1Ot0I2vsWOvoKjOqTml7H/KL9z5EZJWPf/5em80R/4g56YPFRA OTHm86oDVTqvVwfBV+Gx8p7M0QEv X-Google-Smtp-Source: AAOMgpc2d49tGUHDUs4uvGvfmsFzcrcVBjzTXZpz/jkXMQGzEKHOipK6g03H8dv7y8z0cgJ55mvG/g== X-Received: by 2002:a63:35c3:: with SMTP id c186-v6mr9619379pga.217.1530888521403; Fri, 06 Jul 2018 07:48:41 -0700 (PDT) Received: from dsa-mb.local ([2601:284:8200:5cfb:e5bb:a0b3:1b35:a097]) by smtp.googlemail.com with ESMTPSA id i89-v6sm25751817pfi.170.2018.07.06.07.48.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 06 Jul 2018 07:48:40 -0700 (PDT) Subject: Re: [PATCH] ipv4: fib: avoid NULL dereference To: Mark Rutland , linux-kernel@vger.kernel.org Cc: Alexey Kuznetsov , "David S . Miller" , Hideaki YOSHIFUJI , netdev@vger.kernel.org References: <20180706142836.1822-1-mark.rutland@arm.com> From: David Ahern Message-ID: <92672813-153a-eccb-dbee-4b59bbf657f1@gmail.com> Date: Fri, 6 Jul 2018 08:49:14 -0600 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:52.0) Gecko/20100101 Thunderbird/52.9.0 MIME-Version: 1.0 In-Reply-To: <20180706142836.1822-1-mark.rutland@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/6/18 8:28 AM, Mark Rutland wrote: > diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c > index 5bc0c89e81e4..8d98c8162554 100644 > --- a/net/ipv4/fib_trie.c > +++ b/net/ipv4/fib_trie.c > @@ -497,11 +497,11 @@ static void tnode_free(struct key_vector *tn) > struct callback_head *head = &tn_info(tn)->rcu; > > while (head) { > + tn = container_of(head, struct tnode, rcu)->kv; > + > head = head->next; > tnode_free_size += TNODE_SIZE(1ul << tn->bits); > node_free(tn); you are changing tn before the above 2 calls are made on the tn passed in > - > - tn = container_of(head, struct tnode, rcu)->kv; > } > > if (tnode_free_size >= PAGE_SIZE * sync_pages) { >