From patchwork Wed Jun 26 02:33:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 11016879 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 92C22112C for ; Wed, 26 Jun 2019 02:34:53 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 82A05285D4 for ; Wed, 26 Jun 2019 02:34:53 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 768F8285E1; Wed, 26 Jun 2019 02:34:53 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 23AF2285D4 for ; Wed, 26 Jun 2019 02:34:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726543AbfFZCen (ORCPT ); Tue, 25 Jun 2019 22:34:43 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:58708 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726441AbfFZCem (ORCPT ); Tue, 25 Jun 2019 22:34:42 -0400 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 x5Q2T27Q116704; Wed, 26 Jun 2019 02:33:33 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=subject : from : to : cc : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=corp-2018-07-02; bh=mV9lFn0ZU5Q9Z/uVcSNUaPT4H36wgugtQJzUEwexaJw=; b=Bbgfx+OF55IU8/l75LipHQ6ChFrxwEh3rej4w1HwnTiGr/YF8XpRL2Gr3GPLc5TCwsni EZzjsXkEb4i8hu7iHWaB9bnxN6LeEjyXUTH2cFB98jE65Cq+8AUQ4FEmQivvki6SJ5Zf Hho8t8iJZl+aAEcupTrda0bvVui6NciXafJvRqe/3bA4axOe/5sbOwAJr8/nXvuuoQKT 1hFautW0d9ZwytdNz83QDzFzXR0YIzfOmIU7x9qeyprMF5NbacmHfHsaauQ5H6AfjALF vLuw1Tum1ogZV7XwEVxCcFUJlujj07A0PYITiCds/n2YGe3Xyx4D/ChX0QzpclqG4mGi 0g== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 2t9brt7mn5-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 26 Jun 2019 02:33:32 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5Q2XVsr152430; Wed, 26 Jun 2019 02:33:32 GMT Received: from pps.reinject (localhost [127.0.0.1]) by aserp3030.oracle.com with ESMTP id 2t9accehj8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 26 Jun 2019 02:33:32 +0000 Received: from aserp3030.oracle.com (aserp3030.oracle.com [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x5Q2XVTW152431; Wed, 26 Jun 2019 02:33:31 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 2t9accehhg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 26 Jun 2019 02:33:31 +0000 Received: from abhmp0008.oracle.com (abhmp0008.oracle.com [141.146.116.14]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x5Q2XQor012254; Wed, 26 Jun 2019 02:33:26 GMT Received: from localhost (/10.159.230.235) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 25 Jun 2019 19:33:26 -0700 Subject: [PATCH 4/5] vfs: don't allow most setxattr to immutable files From: "Darrick J. Wong" To: matthew.garrett@nebula.com, yuchao0@huawei.com, tytso@mit.edu, darrick.wong@oracle.com, ard.biesheuvel@linaro.org, josef@toxicpanda.com, hch@infradead.org, clm@fb.com, adilger.kernel@dilger.ca, viro@zeniv.linux.org.uk, jack@suse.com, dsterba@suse.com, jaegeuk@kernel.org, jk@ozlabs.org Cc: 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 Date: Tue, 25 Jun 2019 19:33:24 -0700 Message-ID: <156151640402.2283603.11025968584452701508.stgit@magnolia> In-Reply-To: <156151637248.2283603.8458727861336380714.stgit@magnolia> References: <156151637248.2283603.8458727861336380714.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9299 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=895 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906260027 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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." However, we don't actually check the immutable flag in the setattr code, which means that we can update inode flags and project ids and extent size hints on supposedly immutable files. Therefore, reject setflags and fssetxattr calls on an immutable file if the file is immutable and will remain that way. Signed-off-by: Darrick J. Wong --- fs/inode.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/fs/inode.c b/fs/inode.c index cf07378e5731..4261c709e50e 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2214,6 +2214,14 @@ int vfs_ioc_setflags_prepare(struct inode *inode, unsigned int oldflags, !capable(CAP_LINUX_IMMUTABLE)) return -EPERM; + /* + * We aren't allowed to change any other flags if the immutable flag is + * already set and is not being unset. + */ + if ((oldflags & FS_IMMUTABLE_FL) && (flags & FS_IMMUTABLE_FL) && + oldflags != flags) + return -EPERM; + /* * Now that we're done checking the new flags, flush all pending IO and * dirty mappings before setting S_IMMUTABLE on an inode via @@ -2284,6 +2292,25 @@ int vfs_ioc_fssetxattr_check(struct inode *inode, const struct fsxattr *old_fa, !(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) return -EINVAL; + /* + * We aren't allowed to change any fields if the immutable flag is + * already set and is not being unset. + */ + if ((old_fa->fsx_xflags & FS_XFLAG_IMMUTABLE) && + (fa->fsx_xflags & FS_XFLAG_IMMUTABLE)) { + if (old_fa->fsx_xflags != fa->fsx_xflags) + return -EPERM; + if (old_fa->fsx_projid != fa->fsx_projid) + return -EPERM; + if ((fa->fsx_xflags & (FS_XFLAG_EXTSIZE | + FS_XFLAG_EXTSZINHERIT)) && + old_fa->fsx_extsize != fa->fsx_extsize) + return -EPERM; + if ((old_fa->fsx_xflags & FS_XFLAG_COWEXTSIZE) && + old_fa->fsx_cowextsize != fa->fsx_cowextsize) + return -EPERM; + } + /* Extent size hints of zero turn off the flags. */ if (fa->fsx_extsize == 0) fa->fsx_xflags &= ~(FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT);