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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 DAA31C43603 for ; Mon, 9 Dec 2019 02:23:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE24920700 for ; Mon, 9 Dec 2019 02:23:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575858205; bh=ckJe1f9z+0yhWD6XSFJBjDXQNPIHJUlBowWUcrDFwnM=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=RDFJXNeampRpPVZG8yB5SXPD9TqneEjMD3OZshPZ7CJlwQGRs1YckZiFyUj+Iaby/ 7ITAxbeRLw4vow00q2gEhmQKxBdvGW7goUy5qQzLCe2ZKWY5Urk+YY08oIg7DxF8P2 FwtpdMk224qnzPGLmzjvQArkZ2wUr8l4xOvcpbFc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726915AbfLICXX (ORCPT ); Sun, 8 Dec 2019 21:23:23 -0500 Received: from mail-lj1-f193.google.com ([209.85.208.193]:40190 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726635AbfLICXW (ORCPT ); Sun, 8 Dec 2019 21:23:22 -0500 Received: by mail-lj1-f193.google.com with SMTP id s22so13780968ljs.7 for ; Sun, 08 Dec 2019 18:23:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=jtNlyNh+mGdA2q4AO/JzXYXFrnuZqMnTZ+qQdX6qkbw=; b=dZTJ7Zvl+X4Orlt5MxUX7caFe5OE31NxlNViH1WqR1xDkCBQ5UDeD13DvceCigkefe NkUu8l4gfBUHZtIbZVYr5+fPLPBcJzA6yphObSdWg1lXpEgnqyLssA5GvFfNgnMwdzMh tAhKKkBhHK2297EJrC4yT/2mx9cAPYvsAmndE= 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=jtNlyNh+mGdA2q4AO/JzXYXFrnuZqMnTZ+qQdX6qkbw=; b=ByLPVOUatMSZaXpQbV61f53HdwQHrzEWtuD5AC0KtmfCoGYI7mhh5D1gKwWHHX/YE/ 8lnzLEQMbk/P1fYxlCr3hhSPphLpkt8/NocE+Uu7c5EXq0TEUJXN9qBJQmLkgBxeMavo kvokC6L0ajndhTc0PoUTteWS59bPVorEM4aw19RK+tf7qRLlkwv4x57vfAppOR/lvfx1 4x0THeSa1DyG5kwlWAbOe38ZQMZc0oUR6efVz/KfIhWtTQjwaRRrShro1Q0BCss4w8rx Z++myLvX5eO/2EbxoR1+UAt60iHw8UwUbETl64Po7d57v6ES6/45bGecYfreiOCeNvZV sdTw== X-Gm-Message-State: APjAAAVJB94+TrJi0y04c74UanndDGK0MGzOkmk/FGlqXT6aSpsFC9Fw Yq3EpkFl16fxdVYpubrLy/3XbejbQmc= X-Google-Smtp-Source: APXvYqzNVSf5Tiq6B5DYukD6RqIZSYJXtfwwhPGm/5sCBySXKWsDzBa7hBku4XI/afGj/HvT1Z3UAA== X-Received: by 2002:a2e:8646:: with SMTP id i6mr15350900ljj.122.1575858200302; Sun, 08 Dec 2019 18:23:20 -0800 (PST) Received: from mail-lj1-f176.google.com (mail-lj1-f176.google.com. [209.85.208.176]) by smtp.gmail.com with ESMTPSA id f26sm5118148ljn.104.2019.12.08.18.23.19 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 08 Dec 2019 18:23:19 -0800 (PST) Received: by mail-lj1-f176.google.com with SMTP id a13so13762375ljm.10 for ; Sun, 08 Dec 2019 18:23:19 -0800 (PST) X-Received: by 2002:a2e:241a:: with SMTP id k26mr15164274ljk.26.1575858198831; Sun, 08 Dec 2019 18:23:18 -0800 (PST) MIME-Version: 1.0 References: <30808b0b-367a-266a-7ef4-de69c08e1319@internode.on.net> <09396dca-3643-9a4b-070a-e7db2a07235e@internode.on.net> In-Reply-To: <09396dca-3643-9a4b-070a-e7db2a07235e@internode.on.net> From: Linus Torvalds Date: Sun, 8 Dec 2019 18:23:02 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: refcount_t: underflow; use-after-free with CIFS umount after scsi-misc commit ef2cc88e2a205b8a11a19e78db63a70d3728cdf5 To: Arthur Marsh Cc: SCSI development list , Linux Kernel Mailing List , CIFS , "James E.J. Bottomley" 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 Sun, Dec 8, 2019 at 5:49 PM Arthur Marsh wrote: > > This still happens with 5.5.0-rc1: Does it happen 100% of the time? Your bisection result looks pretty nonsensical - not that it's impossible (anything is possible), but it really doesn't look very likely. Which makes me think maybe it's slightly timing-sensitive or something? Would you mind trying to re-do the bisection, and for each kernel try the mount thing at least a few times before you decide a kernel is good? Bisection is very powerful, but if _any_ of the kernels you marked good weren't really good (they just happened to not trigger the problem), bisection ends up giving completely the wrong answer. And with that bisection commit, there's not even a hint of what could have gone wrong. Linus