From patchwork Wed Apr 17 19:05:19 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: 10905963 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 D0FF918FD for ; Wed, 17 Apr 2019 19:05:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C1C6B28B6D for ; Wed, 17 Apr 2019 19:05:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BFAAE28B94; Wed, 17 Apr 2019 19:05:26 +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=-5.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, SUSPICIOUS_RECIPS,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 52A842863F for ; Wed, 17 Apr 2019 19:05:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733198AbfDQTFZ (ORCPT ); Wed, 17 Apr 2019 15:05:25 -0400 Received: from aserp2130.oracle.com ([141.146.126.79]:36572 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729291AbfDQTFY (ORCPT ); Wed, 17 Apr 2019 15:05:24 -0400 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3HIwfwM174822; Wed, 17 Apr 2019 19:05:22 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=65zAMWNbUYxjRT2cZg/WO6PMiXob/jmyxtPBrDUR6D8=; b=xFoILBd6NJ8C+0ltAFOAks1eAAGn4Z8ljn3Winqydz1TrtFh38bVmClNJLmGhYB5fJRC KANcJQgTNRiUXYWEuMtIGB4hJPugi21DMaQScUDNdi1JQ99C7DmxSSi+zEOmSBPv4gMw fvgR/O2lnjyXZEVXlQV39S5ETSVmFeqb2Entnoz8vg97kuVT05NPUK/Gow5qH+GivmV5 vAfEdhGuvKnd86bjckJTngZuHzRNhYElmcelQfzRsLE2rsciSUjxYnfOYTwnpSspqRg5 eQ27/2Fpswz7PFNMSOWvDP5d/NtjfAuQFY8A4X5XtsFVYsK2TkoYSDoUag4l5sq0m3W4 ew== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by aserp2130.oracle.com with ESMTP id 2ru59dcx5k-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 17 Apr 2019 19:05:22 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x3HJ53Sh087410; Wed, 17 Apr 2019 19:05:21 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3030.oracle.com with ESMTP id 2ru4vtyy2g-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 17 Apr 2019 19:05:21 +0000 Received: from abhmp0016.oracle.com (abhmp0016.oracle.com [141.146.116.22]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x3HJ5KBK020437; Wed, 17 Apr 2019 19:05:20 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 17 Apr 2019 12:05:20 -0700 Subject: [PATCH 8/8] ext4: don't allow any modifications to an immutable file From: "Darrick J. Wong" To: darrick.wong@oracle.com Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mm@kvack.org Date: Wed, 17 Apr 2019 12:05:19 -0700 Message-ID: <155552791984.20411.6785112966155823848.stgit@magnolia> In-Reply-To: <155552786671.20411.6442426840435740050.stgit@magnolia> References: <155552786671.20411.6442426840435740050.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9230 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=1 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=594 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904170125 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9230 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=618 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904170125 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Darrick J. Wong Don't allow any modifications to a file that's marked immutable, which means that we have to flush all the writable pages to make the readonly and we have to check the setattr/setflags parameters more closely. Signed-off-by: Darrick J. Wong --- fs/ext4/ioctl.c | 46 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index bab3da4f1e0d..abf3b88d5af7 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -269,6 +269,29 @@ static int uuid_is_zero(__u8 u[16]) } #endif +/* + * If immutable is set and we are not clearing it, we're not allowed to change + * anything else in the inode. Don't error out if we're only trying to set + * immutable on an immutable file. + */ +static int ext4_ioctl_check_immutable(struct inode *inode, __u32 new_projid, + unsigned int flags) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + unsigned int oldflags = ei->i_flags; + + if (!(oldflags & EXT4_IMMUTABLE_FL) || !(flags & EXT4_IMMUTABLE_FL)) + return 0; + + if ((oldflags & ~EXT4_IMMUTABLE_FL) != (flags & ~EXT4_IMMUTABLE_FL)) + return -EPERM; + if (ext4_has_feature_project(inode->i_sb) && + __kprojid_val(ei->i_projid) != new_projid) + return -EPERM; + + return 0; +} + static int ext4_ioctl_setflags(struct inode *inode, unsigned int flags) { @@ -322,6 +345,20 @@ static int ext4_ioctl_setflags(struct inode *inode, goto flags_out; } + /* + * Wait for all pending directio and then flush all the dirty pages + * for this file. The flush marks all the pages readonly, so any + * subsequent attempt to write to the file (particularly mmap pages) + * will come through the filesystem and fail. + */ + if (S_ISREG(inode->i_mode) && !IS_IMMUTABLE(inode) && + (flags & EXT4_IMMUTABLE_FL)) { + inode_dio_wait(inode); + err = filemap_write_and_wait(inode->i_mapping); + if (err) + goto flags_out; + } + handle = ext4_journal_start(inode, EXT4_HT_INODE, 1); if (IS_ERR(handle)) { err = PTR_ERR(handle); @@ -751,7 +788,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return err; inode_lock(inode); - err = ext4_ioctl_setflags(inode, flags); + err = ext4_ioctl_check_immutable(inode, + from_kprojid(&init_user_ns, ei->i_projid), + flags); + if (!err) + err = ext4_ioctl_setflags(inode, flags); inode_unlock(inode); mnt_drop_write_file(filp); return err; @@ -1121,6 +1162,9 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) goto out; flags = (ei->i_flags & ~EXT4_FL_XFLAG_VISIBLE) | (flags & EXT4_FL_XFLAG_VISIBLE); + err = ext4_ioctl_check_immutable(inode, fa.fsx_projid, flags); + if (err) + goto out; err = ext4_ioctl_setflags(inode, flags); if (err) goto out;