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=-0.8 required=3.0 tests=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 B8D2EC2D0DB for ; Tue, 28 Jan 2020 13:47:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9A1E624686 for ; Tue, 28 Jan 2020 13:47:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726327AbgA1Nrw (ORCPT ); Tue, 28 Jan 2020 08:47:52 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:54264 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725852AbgA1Nrv (ORCPT ); Tue, 28 Jan 2020 08:47:51 -0500 Received: from in01.mta.xmission.com ([166.70.13.51]) by out01.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1iwRDY-00020G-C5; Tue, 28 Jan 2020 06:47:48 -0700 Received: from ip68-227-160-95.om.om.cox.net ([68.227.160.95] helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.87) (envelope-from ) id 1iwRDX-0006bg-Ma; Tue, 28 Jan 2020 06:47:48 -0700 From: ebiederm@xmission.com (Eric W. Biederman) To: Christian Brauner Cc: Greg Kroah-Hartman , Dmitry Vyukov , Christian Brauner , Hridya Valsaraju , Arve =?utf-8?B?SGrDuG5uZXbDpWc=?= , Todd Kjos , Martijn Coenen , Joel Fernandes , "open list\:ANDROID DRIVERS" , LKML , syzkaller References: <20200126085535.GA3533171@kroah.com> <20200126093506.oa2ee5kbptur4zhz@wittgenstein> Date: Tue, 28 Jan 2020 07:46:08 -0600 In-Reply-To: <20200126093506.oa2ee5kbptur4zhz@wittgenstein> (Christian Brauner's message of "Sun, 26 Jan 2020 10:35:07 +0100") Message-ID: <87blqn3d9b.fsf@x220.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1iwRDX-0006bg-Ma;;;mid=<87blqn3d9b.fsf@x220.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.160.95;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19TaqhwtfnOs4J3o+rZtj2FKDMPKZsQpjA= X-SA-Exim-Connect-IP: 68.227.160.95 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: binderfs interferes with syzkaller? X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christian Brauner writes: > On Sun, Jan 26, 2020 at 09:55:35AM +0100, Greg Kroah-Hartman wrote: >> On Sat, Jan 25, 2020 at 06:49:49PM +0100, Dmitry Vyukov wrote: >> > Hi binder maintainers, >> > >> > It seems that something has happened and now syzbot has 0 coverage in >> > drivers/android/binder.c: >> > https://storage.googleapis.com/syzkaller/cover/ci-upstream-kasan-gce-root.html >> > It covered at least something there before as it found some bugs in binder code. >> > I _suspect_ it may be related to introduction binderfs, but it's >> > purely based on the fact that binderfs changed lots of things there. >> > And I see it claims to be backward compatible. >> >> It is backwards compatible if you mount binderfs, right? > > Yes, it is backwards compatible. The devices that would usually be > created in devtmpfs are now created in binderfs. The core > binder-codepaths are the same. Any chance you can add code to the binderfs case to automatically create the symlinks to the standard mount location in devtmpfs? That way existing userspace might not need to care how the kernel is configured. Eric