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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 62A3AC7618F for ; Mon, 15 Jul 2019 16:35:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37E3920838 for ; Mon, 15 Jul 2019 16:35:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563208503; bh=P7A+7gOxObkHWO6q15pHPOZJY3ZnoB4xnL29l3PZe7s=; h=Date:From:To:Subject:References:In-Reply-To:List-ID:From; b=Buf5Ku1CWcIXb1OB+3Th+XMuyIblK1LPZqABtJHfPZ7yxTglu7qdVpFCLBxu9AENf cV1H0jMeedeLxYM+y2AlzEMKNF+Ehea3vNzDov0FGFhzZymnkZ4TdSfefUVaXoHUb4 YD/38fm/GFBRFxqxxofoJ5k4GvbG91ZQlu3YmHG0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730520AbfGOQfC (ORCPT ); Mon, 15 Jul 2019 12:35:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:57216 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729533AbfGOQfC (ORCPT ); Mon, 15 Jul 2019 12:35:02 -0400 Received: from sol.localdomain (c-24-5-143-220.hsd1.ca.comcast.net [24.5.143.220]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6DCDB2081C; Mon, 15 Jul 2019 16:35:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563208501; bh=P7A+7gOxObkHWO6q15pHPOZJY3ZnoB4xnL29l3PZe7s=; h=Date:From:To:Subject:References:In-Reply-To:From; b=qRoAXzIa+pdRPCFXmxYW6ryLdJ2CjbYC4GD+SDb0fQBtStL6KbuhUqmyfRlQFh0g9 n7FqCIbiLmWySaaO1UByUZU6qPSTydhuwChSZkbatxzPJt+c+rFLYo1pUpwziZeyas 4AoxFsumGv8w82GA/mGC5+C1YtW4PbLtSrEmfv4g= Date: Mon, 15 Jul 2019 09:34:59 -0700 From: Eric Biggers To: Mimi Zohar , syzbot , dmitry.kasatkin@gmail.com, jmorris@namei.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, serge@hallyn.com, syzkaller-bugs@googlegroups.com, zohar@linux.vnet.ibm.com Subject: Re: possible deadlock in process_measurement Message-ID: <20190715163459.GB728@sol.localdomain> Mail-Followup-To: Mimi Zohar , syzbot , dmitry.kasatkin@gmail.com, jmorris@namei.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, serge@hallyn.com, syzkaller-bugs@googlegroups.com, zohar@linux.vnet.ibm.com References: <00000000000054e5d1058a6df2eb@google.com> <1562854476.4014.47.camel@linux.ibm.com> <20190711195011.GA48706@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20190711195011.GA48706@gmail.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On Thu, Jul 11, 2019 at 12:50:13PM -0700, Eric Biggers wrote: > Hi Mimi, > > On Thu, Jul 11, 2019 at 10:14:36AM -0400, Mimi Zohar wrote: > > Hi Eric, > > > > On Mon, 2019-06-03 at 09:35 -0700, syzbot wrote: > > > syzbot has found a reproducer for the following crash on: > > > > > > HEAD commit: 3c09c195 Add linux-next specific files for 20190531 > > > git tree: linux-next > > > console output: https://syzkaller.appspot.com/x/log.txt?x=10f61a0ea00000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=6cfb24468280cd5c > > > dashboard link: https://syzkaller.appspot.com/bug?extid=5ab61747675a87ea359d > > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=177c3d16a00000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14ec01baa00000 > > > > > > > This reproducer seems like it is similar, but the cause is different > > than the original report.  One has to do with overlayfs, while the > > other has to do with ext4, mprotect/mmap.  I assume in both cases an > > IMA policy was required to trigger the locking bug.  What type of IMA > > policy are you using? > > > > Do we need to differentiate the two reports?  Is the "last occurred" > > notification for the overlay, for mprotect, or both?  Please Cc the > > overlay mailing list on the overlay aspect. > > AFAICS, syzbot boots all kernels with "ima_policy=tcb" on the command line. > And I don't think anything in userspace changes the IMA policy. > > It's not unusual for multiple underlying bugs to get mixed into the same syzbot > bug. syzbot doesn't know that one "possible deadlock in process_measurement" is > different from another. "Last occurred" is for any crash that appeared as such. > > This just needs to be handled the best we can. Sometimes all the bugs can be > fixed; sometimes they've already been fixed; or sometimes it's easiest to fix > just one and then mark the syzbot bug as fixed, and syzbot will report it again > it's still occurring for some other reason. > > - Eric Invalidating this bug report as per the discussion at https://lkml.kernel.org/linux-integrity/1563122888.4539.119.camel@linux.ibm.com/T/#mcd083826e5843f048c914c56a4e82147fc211704 #syz invalid For future reference, anyone can update the status of syzbot bugs; no need to ask me to do it. See https://goo.gl/tpsmEJ#status - Eric