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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_MUTT autolearn=ham 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 67D6FC48BE3 for ; Thu, 20 Jun 2019 22:13:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2DC5C2070B for ; Thu, 20 Jun 2019 22:13:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="HRHy43z6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2DC5C2070B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=oracle.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B71C06B0005; Thu, 20 Jun 2019 18:13:23 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AFC3A8E0002; Thu, 20 Jun 2019 18:13:23 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 99B508E0001; Thu, 20 Jun 2019 18:13:23 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-vk1-f199.google.com (mail-vk1-f199.google.com [209.85.221.199]) by kanga.kvack.org (Postfix) with ESMTP id 72A396B0005 for ; Thu, 20 Jun 2019 18:13:23 -0400 (EDT) Received: by mail-vk1-f199.google.com with SMTP id m1so1753170vkl.11 for ; Thu, 20 Jun 2019 15:13:23 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:date:from:to:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=OsSBTvuyKOZHpYxr7BMRKlrDJF74SMWishCpQlewDkg=; b=HmkA9L/8Gmtr0H/joT7wJyC9F0lu7AQesPOxpd5CxfA61PrW/rFlTem0hTdHFToXP2 03d2NJ703iKnIq3e3ho/2O0yYxX1SU6cfCz+PCDK3G76ph9P+EVg8TeAqBzfPtEK20OM qY01KmovhZ6F2F6s4KhHlgE7ZDzmhkafwBapDe1Yqq2WESh4UcxwCXJx/35tRZcF/MJw /i1jQzb+SjBeTqnC5BweoFSf7rxXDqTxMdeRTGyuRYRGuDHYLxrD65+brjRJGQghASAH ZQ7UfXBPFuFxOSA44n4aNLhRk+7YyQ71ygfQjUovkXQfdlUpHiowSEJzTMQWGUX4FAYj dq1w== X-Gm-Message-State: APjAAAWnpuj1PGTU8yEQj6zbj7vEP1vsW+MMZWG+EByTaPu3vqjTF7Vz 07qPqEqm8uGP6IFaNL1egqFlP1FvblQLbmG7Nnjg6osGTwnQSCEWqk/wsyvPwLj9O0rmZzYKs5y aXizeqfeoDJ1zgUsuwwN/RUQb6PhZlzJyCCkE91x8oGh6/qBOKppartVMAImZzmdcsA== X-Received: by 2002:ab0:5499:: with SMTP id p25mr66411979uaa.2.1561068803052; Thu, 20 Jun 2019 15:13:23 -0700 (PDT) X-Google-Smtp-Source: APXvYqy1HbELUbZLYUZDvbbj77SjiUrPyoFqTwpr+g+MDcVfioUbLjVY8XcoSag4Omi7mIWDfaUT X-Received: by 2002:ab0:5499:: with SMTP id p25mr66411948uaa.2.1561068802450; Thu, 20 Jun 2019 15:13:22 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1561068802; cv=none; d=google.com; s=arc-20160816; b=LvWILLxUGfG6Wvv9iHHwE4BsnLhWilnhmeSPBcWbGHxsFUhG0kPalxLuQu0PPlgEeq pAkHEB0OoFbvSz2pVRqkoDiadc9YbrjgPrFEE97jrkP0kFz8woc0jJBbHTv6iK8YWiGK hL0EP1cx9fGqpyainFSTWf8NmL0bvjtSp5NDriWehml1vAZVuaapr4ES6W5/S5lYD/SZ RoViSFa8coazC5v6PUZknz3JO/LOfmEVCrRN/qeVMKJgCi1Z4AwjM+ufDESi9/wf6jZg prP4C8zpCL57NbkgH3v/o1eTF+5MMTqSUrU0Q46wHJ7TRzq3iT/Rawx7Kl7NLg9/RQtk T3xw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:to:from:date:dkim-signature; bh=OsSBTvuyKOZHpYxr7BMRKlrDJF74SMWishCpQlewDkg=; b=l6PSPD0LNMRukNuM8kRIh409TPby5xP/8WBWVB5iTZxqQ1uKfNDhZMNaqqw82F4Rue +JNgj3YjnrRUQtgWAjzj9ecCCTW9XzTQ7gThlN45ZVAN7L7KmTIlvp6SdF4CHctKYIIS e7MIScbOwy2MmnB0jsTpN3ccsjtUkK7e2k4sBVfiF3KlVT61ky9WjZEG9cQyQ7XXAxwZ QlCbgcjH0twefmhIAsO1q4ylXPq9l7P2iu+pETVv/WwCexsrWEUamC0EtMdv1PzZZtlS i5m/jf8UfjgGRNsUaMK48GmK5ocdTHvVyk/eSReO0/77ZprbpnBCgNpt7CemQoU1u+n5 ZBVw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2018-07-02 header.b=HRHy43z6; spf=pass (google.com: domain of darrick.wong@oracle.com designates 156.151.31.86 as permitted sender) smtp.mailfrom=darrick.wong@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: from userp2130.oracle.com (userp2130.oracle.com. [156.151.31.86]) by mx.google.com with ESMTPS id w8si131720uag.240.2019.06.20.15.13.21 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 20 Jun 2019 15:13:22 -0700 (PDT) Received-SPF: pass (google.com: domain of darrick.wong@oracle.com designates 156.151.31.86 as permitted sender) client-ip=156.151.31.86; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2018-07-02 header.b=HRHy43z6; spf=pass (google.com: domain of darrick.wong@oracle.com designates 156.151.31.86 as permitted sender) smtp.mailfrom=darrick.wong@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5KM3nsv109072; Thu, 20 Jun 2019 22:13:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2018-07-02; bh=OsSBTvuyKOZHpYxr7BMRKlrDJF74SMWishCpQlewDkg=; b=HRHy43z65mymGGo6sWVVPuVFpItbR12cz3YFYbaCqJGOBgvqYtfpb/PeLVjuuEVqrQv2 GpZIrIgzJZC0+U+yXwJ1Vqs3qY3UMIfqSIwL3pZPIfdyZff3jwYOEkEcKtjd/YwH/Sq6 aV/5TlsmcdKu7KhrpVNfWRmjrbQlir4Di4CKy0hExq7FpxJJYc99Sw4feLIcaNKWlvrK 5xy4bURhqhJGb38LoU38YZ1npKwLTXMnl7fXFWWSALJ4esecgPStCOfTzz7/fuGUuQ5/ 3Ls5Aj1t1c7iY5R0EC3GWYb2yjGGpkr0/0/gtaJLRnwOzAdzATduot/C0pAUHfoTLX0u QQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by userp2130.oracle.com with ESMTP id 2t7809kgm8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 20 Jun 2019 22:13:13 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5KMCXI6043214; Thu, 20 Jun 2019 22:13:12 GMT Received: from pps.reinject (localhost [127.0.0.1]) by aserp3020.oracle.com with ESMTP id 2t77ypm9eb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 20 Jun 2019 22:13:12 +0000 Received: from aserp3020.oracle.com (aserp3020.oracle.com [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x5KMDCTk044443; Thu, 20 Jun 2019 22:13:12 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserp3020.oracle.com with ESMTP id 2t77ypm9e2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 20 Jun 2019 22:13:12 +0000 Received: from abhmp0019.oracle.com (abhmp0019.oracle.com [141.146.116.25]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x5KMD85F022773; Thu, 20 Jun 2019 22:13:09 GMT Received: from localhost (/10.145.179.81) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 20 Jun 2019 15:13:08 -0700 Date: Thu, 20 Jun 2019 15:13:06 -0700 From: "Darrick J. Wong" To: "Theodore Ts'o" , matthew.garrett@nebula.com, yuchao0@huawei.com, ard.biesheuvel@linaro.org, josef@toxicpanda.com, clm@fb.com, adilger.kernel@dilger.ca, viro@zeniv.linux.org.uk, jack@suse.com, dsterba@suse.com, jaegeuk@kernel.org, jk@ozlabs.org, reiserfs-devel@vger.kernel.org, linux-efi@vger.kernel.org, devel@lists.orangefs.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-nilfs@vger.kernel.org, linux-mtd@lists.infradead.org, ocfs2-devel@oss.oracle.com, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org Subject: Re: [PATCH 1/6] mm/fs: don't allow writes to immutable files Message-ID: <20190620221306.GD5375@magnolia> References: <156022836912.3227213.13598042497272336695.stgit@magnolia> <156022837711.3227213.11787906519006016743.stgit@magnolia> <20190620215212.GG4650@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190620215212.GG4650@mit.edu> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9294 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=570 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906200158 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jun 20, 2019 at 05:52:12PM -0400, Theodore Ts'o wrote: > On Mon, Jun 10, 2019 at 09:46:17PM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > The chattr manpage has this to say about immutable files: > > > > "A file with the 'i' attribute cannot be modified: it cannot be deleted > > or renamed, no link can be created to this file, most of the file's > > metadata can not be modified, and the file can not be opened in write > > mode." > > > > Once the flag is set, it is enforced for quite a few file operations, > > such as fallocate, fpunch, fzero, rm, touch, open, etc. However, we > > don't check for immutability when doing a write(), a PROT_WRITE mmap(), > > a truncate(), or a write to a previously established mmap. > > > > If a program has an open write fd to a file that the administrator > > subsequently marks immutable, the program still can change the file > > contents. Weird! > > > > The ability to write to an immutable file does not follow the manpage > > promise that immutable files cannot be modified. Worse yet it's > > inconsistent with the behavior of other syscalls which don't allow > > modifications of immutable files. > > > > Therefore, add the necessary checks to make the write, mmap, and > > truncate behavior consistent with what the manpage says and consistent > > with other syscalls on filesystems which support IMMUTABLE. > > > > Signed-off-by: Darrick J. Wong > > I note that this patch doesn't allow writes to swap files. So Amir's > generic/554 test will still fail for those file systems that don't use > copy_file_range. I didn't add any IS_SWAPFILE checks here, so I'm not sure to what you're referring? > I'm indifferent as to whether you add a new patch, or include that > change in this patch, but perhaps we should fix this while we're > making changes in these code paths? The swapfile patches should be in a separate patch, which I was planning to work on but hadn't really gotten around to it. --D > - Ted