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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 40438CCA473 for ; Fri, 24 Jun 2022 06:56:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230301AbiFXG4z (ORCPT ); Fri, 24 Jun 2022 02:56:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230220AbiFXG4y (ORCPT ); Fri, 24 Jun 2022 02:56:54 -0400 Received: from mail-pf1-x432.google.com (mail-pf1-x432.google.com [IPv6:2607:f8b0:4864:20::432]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 30FCB67E7B; Thu, 23 Jun 2022 23:56:53 -0700 (PDT) Received: by mail-pf1-x432.google.com with SMTP id 65so1744822pfw.11; Thu, 23 Jun 2022 23:56:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=CQLW04s8vb4y/9XuYLHdde+ABYigEI4asQuaKgLJKrc=; b=EaJlsD5vomAKolqToFKbaK9jwrVvh6ooFjnstoPX7A0a2umRNYpz9NH3KVmtY32G2B Z4bLBwWRl9uhoasIHDdcc0KQsrwKQZv9VvU01IopJVPIUBlIMIJvOfnu6MdnHgDfh+R/ 7HkwqeOZxFh4Vr5R/T0/yUt4MWFSjHTHXT5zFX5xC3eFhJ0HjCnQ6nSNzOVddcUL36Um /EaACA5h/5jcM9LgrgwK8gw/bIBn2/maGcajsmMxsUUVbIThGdxN8OPvBY+8Ap82xzCm NXX9mNyyt0URHsVvVPA3+b3RzFREjJ4Fm89nB9WyMb+8XXVrakT1VRbIzyj5Ryya9u3U Qojg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=CQLW04s8vb4y/9XuYLHdde+ABYigEI4asQuaKgLJKrc=; b=MYzRDJ2s5+B3ku/692qVpek7T8DA8Ae0hxIei/Od71t/Qza5P17xBSQMPRhmV8k5Xe uchBIiGmkkiTK3IyOD5U8SOa5tqBQzpgUSc4nsSDoBhS+ZQV/0Ju/Nu5CZWpjfLef3b4 IiKVYrTFgcParMA85w/9p5uvGBHw7uBWEvO5K60f5kLHPld+QmvFHqTIpuTV6tF+5qq0 /x3WXVuzgVEIqQqNoS0rvRxgWyWhuUEGQlQ70PhCD6qc668sA/gdGytxkQhiM9EGaOQB 6tUGoDM6LVg4tAX2bSo22HD2owVrkEMpbT3E0K4u3uxzYNpHa97kVmIyLZcrRTm4xsAU rDMg== X-Gm-Message-State: AJIora/8HNLZyR+UfCLnA09fRfGR/SnKnMoBrJFLQM8e/Psfyq1LFWsS oAZMvpjUgk5/mCK3nPiCzc/GpubfFAt1cQ== X-Google-Smtp-Source: AGRyM1vE7dCW7jW8K5Sj06K5myCG9Uagi6GaFVdToms/HjUTM7g5G2vtGxXs54WjU2i5Yk8Z8Vx0Ww== X-Received: by 2002:a63:680a:0:b0:40d:bb2:19f4 with SMTP id d10-20020a63680a000000b0040d0bb219f4mr10564952pgc.593.1656053812518; Thu, 23 Jun 2022 23:56:52 -0700 (PDT) Received: from archdragon (dragonet.kaist.ac.kr. [143.248.133.220]) by smtp.gmail.com with ESMTPSA id 9-20020a170902c20900b0015e8d4eb1dfsm985871pll.41.2022.06.23.23.56.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jun 2022 23:56:52 -0700 (PDT) Date: Fri, 24 Jun 2022 15:56:48 +0900 From: "Dae R. Jeong" To: Eric Dumazet Cc: David Miller , Jakub Kicinski , Paolo Abeni , netdev , LKML Subject: Re: KASAN: use-after-free Read in cfusbl_device_notify Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Jun 24, 2022 at 08:32:31AM +0200, Eric Dumazet wrote: > On Fri, Jun 24, 2022 at 8:25 AM Dae R. Jeong wrote: > > > > On Fri, Jun 24, 2022 at 08:15:54AM +0200, Eric Dumazet wrote: > > > On Fri, Jun 24, 2022 at 8:08 AM Dae R. Jeong wrote: > > > > > > > > Hello, > > > > > > > > We observed a crash "KASAN: use-after-free Read in cfusbl_device_notify" during fuzzing. > > > > > > This is a known problem. > > > > > > Some drivers do not like NETDEV_UNREGISTER being delivered multiple times. > > > > > > Make sure in your fuzzing to have NET_DEV_REFCNT_TRACKER=y > > > > > > Thanks. > > > > Our config already have CONFIG_NET_DEV_REFCNT_TRACKER=y. > > Are you also setting netdev_unregister_timeout_secs to a smaller value ? > > netdev_unregister_timeout_secs > ------------------------------ > > Unregister network device timeout in seconds. > This option controls the timeout (in seconds) used to issue a warning while > waiting for a network device refcount to drop to 0 during device > unregistration. A lower value may be useful during bisection to detect > a leaked reference faster. A larger value may be useful to prevent false > warnings on slow/loaded systems. > Default value is 10, minimum 1, maximum 3600. We are using the same config that Syzkaller uses. So its value is 140. I'm not a network developer so I don't know whether there is a possibility of a false alarm. Our fuzzer is a research prototype in development, and I don't want to interrupt you with false alarms... > > Anyway, this UAF report seems not interesting. > > > > Thank you for your quick reply. > > > > > > Best regards, > > Dae R. Jeong. Best regards, Dae R. Jeong.