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=-1.1 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 DF2CBC43142 for ; Tue, 31 Jul 2018 23:03:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 58D6B20857 for ; Tue, 31 Jul 2018 23:03:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TfpOMOIF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 58D6B20857 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 S1732754AbeHAAqC (ORCPT ); Tue, 31 Jul 2018 20:46:02 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:40782 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732635AbeHAAqC (ORCPT ); Tue, 31 Jul 2018 20:46:02 -0400 Received: by mail-pg1-f195.google.com with SMTP id x5-v6so9801258pgp.7; Tue, 31 Jul 2018 16:03:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=VdDueqK6PylNDDUcXZW53jNcTL6y61lbYsweGP8iE50=; b=TfpOMOIFpHFvfgcKyT1oSnoc12CZ2kzFzRlxUX3a6nd+3lL47Hj9o+I/B80QpGgVPH c8VRxYFgXs7QJOl/d6uObrg1KKWgDPGm2hErCTil6uKc71rT8zOJB4pM5rjAI4qTZgwC y1Cwi3TypK9UHxYFe6HlWCveOybCzw441cNvRKSVbCN2Lar+Rx3XBISbD0Nm1XLo9Pzd sgj+GpiAV+miGr0CUheig96bnjkWOakSO2vgl85a5W2lJ1i3oT7lmz4Tg+YuOJD7bJE1 l7qiRF1V+/i3g0VG5GqfqJCXeuODjZ56wu1Vgq3eZqTuS/HzVPx9pBAU6CM13fpgTjZL j0ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=VdDueqK6PylNDDUcXZW53jNcTL6y61lbYsweGP8iE50=; b=iZUp+OcmJdG9sNXZCvdNI4XOJn3rX8DZQzG48DrkjMKZMDneT6DD/bbwP4S6AamPKc h706XB8jEi20vLmhr+PMu5pceyjTfeSRpEQOc/QePhPlyuatpcgX82XofoZSN77aHMBT m2RPXNPcT33NVu1UUUwNvYjp8iOnhLAwE4+pg/26IWOu0OGg7LJmegpRlE5agCy9phmT 9/zgHhOEYwFvc2qyl/W3q2MTnYB+rKBa8qs+jBtySmG0KOXzKGOX0PRpaMdIzawO9rQx 2v6mmPbIx6BOBM73V6kzVHXpgt6Umr+Rk0N6/2j2jcMtPvkRSw0q1BwUCcsLLrVm0Q34 Q+jw== X-Gm-Message-State: AOUpUlG1mnaNuRwzIoGyDxoM+gfgmHqqutydLibtFtuoHbqpkutyBS/7 hFYJfuyOopeI7fRGinNFgk+7RFo47CPXdcUQQtE= X-Google-Smtp-Source: AAOMgpd8ZHBjRNiSRK3mYYhEyW7wSW+VrTWO8qSSO3f2mbm8omn8RFT5tx/QDc8nYLNe2N2nQ6xIlHXqsFIui4zWduw= X-Received: by 2002:a63:b445:: with SMTP id n5-v6mr22545841pgu.104.1533078205813; Tue, 31 Jul 2018 16:03:25 -0700 (PDT) MIME-Version: 1.0 References: <0000000000004fe2be05724ac084@google.com> <20180731134014.GA32114@bistromath.localdomain> In-Reply-To: <20180731134014.GA32114@bistromath.localdomain> From: Cong Wang Date: Tue, 31 Jul 2018 16:03:13 -0700 Message-ID: Subject: Re: KASAN: use-after-free Read in rtnetlink_put_metrics To: Sabrina Dubroca Cc: Eric Dumazet , syzbot+41f9c04b50ef70c66947@syzkaller.appspotmail.com, christian.brauner@ubuntu.com, David Miller , David Ahern , Florian Westphal , Jiri Benc , Kirill Tkhai , LKML , lucien xin , Linux Kernel Network Developers , syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 31, 2018 at 6:41 AM Sabrina Dubroca wrote: > > 2018-07-31, 05:41:56 -0700, Eric Dumazet wrote: > > > > > > On 07/31/2018 05:31 AM, syzbot wrote: > > > Hello, > > > > > > syzbot found the following crash on: > > > > > > HEAD commit: 61f4b23769f0 netlink: Don't shift with UB on nlk->ngroups > > > git tree: net > > > console output: https://syzkaller.appspot.com/x/log.txt?x=14a9de58400000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=ffb4428fdc82f93b > > > dashboard link: https://syzkaller.appspot.com/bug?extid=41f9c04b50ef70c66947 > > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > > > > > Unfortunately, I don't have any reproducer for this crash yet. > [...] > > > Probably also caused by : > > > > > > commit df18b50448fab1dff093731dfd0e25e77e1afcd1 > > Author: Sabrina Dubroca > > Date: Mon Jul 30 16:23:10 2018 +0200 > > > > net/ipv6: fix metrics leak > > Yeah, I'm looking into both those reports :/ Looks like this commit is completely unnecessary, fib6_drop_pcpu_from() calls fib6_info_release() which calls fib6_info_destroy_rcu(), so this metrics will be released twice...