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=-5.6 required=3.0 tests=BAYES_00,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 646B8C43461 for ; Mon, 14 Sep 2020 20:07:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26CA920E65 for ; Mon, 14 Sep 2020 20:07:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Ynq1XjQq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726046AbgINUHD (ORCPT ); Mon, 14 Sep 2020 16:07:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725953AbgINUHC (ORCPT ); Mon, 14 Sep 2020 16:07:02 -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 2DD86C06174A for ; Mon, 14 Sep 2020 13:07:02 -0700 (PDT) Received: by mail-pf1-x432.google.com with SMTP id v196so538080pfc.1 for ; Mon, 14 Sep 2020 13:07:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=VZ4bLQT3z6JaXubPXGB1pmNC9qXVT9dzt/Q3tQB/tJE=; b=Ynq1XjQqQyqDzGcbEpWuR+tn8iotDeNo64ENelIwB9piSHm41iSt9i3f39rH5D+om1 keERJULeng1WXMMYCXPhEtW5SyxHlU8TiH52fpFeD8Pp6fdsI9afZXxlrtE30Z/5Q/tj Hc82oW6G31/pwJgEC8nt/ainOoG/8YaoIIiRU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=VZ4bLQT3z6JaXubPXGB1pmNC9qXVT9dzt/Q3tQB/tJE=; b=YDFw9Tnr9kBV+Un3wHWJgThn4/2eqsmmS+hSQh2VsOuPwc8BD/djXGomTz6dcI0717 2Sdp0IcNqPq4vWq0EreUYs3LN85d+FjwvcgpZGbWhUF7OMI5Au8/2T8hbtyd28A3w42c tHJS2duqitV5XS/F61n7UT9OOul+1BO2Jrjm5vyyUJYJZ8GPYBhNsDM7gIPhbDs+sSuJ 2q0SUrtZMXM1OXi0YfBvLAT4syIlmaKxOEXVZWPjUC6/A/FQENJj9Fpl5n29QGsn9kSM SreEDAJor2rwSsVzIw3exh0fgeJsut7kQxbv3CzwtXkWljiiNvfkMMXAaOv8tqCAJucD gH1w== X-Gm-Message-State: AOAM5309TQVVaTTt3fQw766abRX7xnGTO0XmhNls6rQBgqDb0OyWAyzf jk1iiuWfcTaAB0U4CiCkOm3hJnWeIjJX0Od0 X-Google-Smtp-Source: ABdhPJzaUD4byUjS+FfCzp5HP+hvFNCdMQPnI06A7ZsWWF5rIFk/LVI1jTpSrEU7+maEGPMn3CZRLg== X-Received: by 2002:a62:5f02:0:b029:13c:1611:6536 with SMTP id t2-20020a625f020000b029013c16116536mr14113247pfb.8.1600114021316; Mon, 14 Sep 2020 13:07:01 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id c22sm9060914pgb.52.2020.09.14.13.07.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Sep 2020 13:07:00 -0700 (PDT) Date: Mon, 14 Sep 2020 13:06:59 -0700 From: Kees Cook To: Thomas Gleixner Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, syzbot , syzkaller-bugs@googlegroups.com, Andy Lutomirski , Peter Zijlstra Subject: Re: WARNING in syscall_exit_to_user_mode Message-ID: <202009141304.811BAC4A0@keescook> References: <00000000000018a47605af074c7d@google.com> <202009121050.0D9CAB95@keescook> <87sgblpi4l.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87sgblpi4l.fsf@nanos.tec.linutronix.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 13, 2020 at 09:54:34PM +0200, Thomas Gleixner wrote: > On Sat, Sep 12 2020 at 10:52, Kees Cook wrote: > >> ------------[ cut here ]------------ > >> syscall 56 left IRQs disabled > > > > This WARN appears reachable. :) > > The above is hardly a problem of the new entry code. It's just detecting > the wreckage... Oh, well that's actually even better! :) > > I also see on the dashboard these other problems with the new entry > > code: > > > https://syzkaller.appspot.com/bug?extid=d4336c84ed0099fdbe47 > > This one is also just the messenger. That's the > > lockdep_assert_irqs_disabled(); > > in irqentry_exit() if I'm reading the reports correctly. That's a #PF > returning with interrupts enabled for whatever weird reason. Let me > stare at that... Cool; thanks. > > https://syzkaller.appspot.com/bug?extid=c4af95386364bc59b13e > > This one is not a new entry code problem either: > [...] > The new entry code is just in the stack trace because that task was > preempted after a timer interrupt. This seems a bit like the first issue: it's just getting noticed now? -- Kees Cook