From patchwork Wed Jun 26 02:33:31 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: 11016891 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 7A045112C for ; Wed, 26 Jun 2019 02:36:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 69BC6285E0 for ; Wed, 26 Jun 2019 02:36:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5DF2A285E3; Wed, 26 Jun 2019 02:36:55 +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 EF24F285E0 for ; Wed, 26 Jun 2019 02:36:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726757AbfFZCgp (ORCPT ); Tue, 25 Jun 2019 22:36:45 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:59564 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726721AbfFZCgp (ORCPT ); Tue, 25 Jun 2019 22:36:45 -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 x5Q2Z0Zp120740; Wed, 26 Jun 2019 02:35:36 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=RDkQFwhFFQ2vI5qz0xIqaf4zf8uM8p//mWlaoaNYF+I=; b=Qi2NwHnVvWi7uetKAFrtDLbEc7vBEztBO544xnn041sSZ7Fd3ocayxJrgUVLY5aWK0nf Ite4JKYpy0UTn6/XETb7boW3RhaAdXiKa1fL2V5TysE/aV9BaTPrGmv7gGnaw4E3aPVd h1eAr0iXSQgZ8bt1cz+Y/aA8/0mIndivv/2HisCjrSY7yBaaGjEge4/5om9TBbv2jvW3 eOfa1J2vXFZDfhPdb+EttM0EV/jAq/YuGxJoz8dMa6tkFMJao88u3rFVpg9bj4ZNDBKS k6bGwT+rfiYQyJ1DPmadzn9S646qAfU1gSQw1fIjxewe/fI4Upnp6HJpT25nXB2TRGu8 EA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2130.oracle.com with ESMTP id 2t9brt7mt2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 26 Jun 2019 02:35:36 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5Q2XQY8081296; Wed, 26 Jun 2019 02:33:36 GMT Received: from pps.reinject (localhost [127.0.0.1]) by userp3020.oracle.com with ESMTP id 2tat7cjp2n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 26 Jun 2019 02:33:36 +0000 Received: from userp3020.oracle.com (userp3020.oracle.com [127.0.0.1]) by pps.reinject (8.16.0.27/8.16.0.27) with SMTP id x5Q2XZtv081761; Wed, 26 Jun 2019 02:33:35 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by userp3020.oracle.com with ESMTP id 2tat7cjp28-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 26 Jun 2019 02:33:35 +0000 Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x5Q2XY3k021348; Wed, 26 Jun 2019 02:33:34 GMT Received: from localhost (/10.159.230.235) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 25 Jun 2019 19:33:34 -0700 Subject: [PATCH 5/5] vfs: don't allow writes to swap 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 19:33:31 -0700 Message-ID: <156151641177.2283603.7806026378321236401.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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906260028 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 Don't let userspace write to an active swap file because the kernel effectively has a long term lease on the storage and things could get seriously corrupted if we let this happen. Signed-off-by: Darrick J. Wong --- fs/attr.c | 3 +++ mm/filemap.c | 3 +++ mm/memory.c | 4 +++- mm/mmap.c | 2 ++ mm/swapfile.c | 15 +++++++++++++-- 5 files changed, 24 insertions(+), 3 deletions(-) diff --git a/fs/attr.c b/fs/attr.c index 1fcfdcc5b367..42f4d4fb0631 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -236,6 +236,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **de if (IS_IMMUTABLE(inode)) return -EPERM; + if (IS_SWAPFILE(inode)) + return -ETXTBSY; + if ((ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) && IS_APPEND(inode)) return -EPERM; diff --git a/mm/filemap.c b/mm/filemap.c index dad85e10f5f8..fd80bc20e30a 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2938,6 +2938,9 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) if (IS_IMMUTABLE(inode)) return -EPERM; + if (IS_SWAPFILE(inode)) + return -ETXTBSY; + if (!iov_iter_count(from)) return 0; diff --git a/mm/memory.c b/mm/memory.c index 4311cfdade90..c04c6a689995 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2235,7 +2235,9 @@ static vm_fault_t do_page_mkwrite(struct vm_fault *vmf) vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; - if (vmf->vma->vm_file && IS_IMMUTABLE(file_inode(vmf->vma->vm_file))) + if (vmf->vma->vm_file && + (IS_IMMUTABLE(file_inode(vmf->vma->vm_file)) || + IS_SWAPFILE(file_inode(vmf->vma->vm_file)))) return VM_FAULT_SIGBUS; ret = vmf->vma->vm_ops->page_mkwrite(vmf); diff --git a/mm/mmap.c b/mm/mmap.c index ac1e32205237..031807339869 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1488,6 +1488,8 @@ unsigned long do_mmap(struct file *file, unsigned long addr, return -EACCES; if (IS_IMMUTABLE(file_inode(file))) return -EPERM; + if (IS_SWAPFILE(file_inode(file))) + return -ETXTBSY; } /* diff --git a/mm/swapfile.c b/mm/swapfile.c index 596ac98051c5..1ca4ee8c2d60 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -3165,6 +3165,19 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) if (error) goto bad_swap; + /* + * Flush any pending IO and dirty mappings before we start using this + * swap file. + */ + if (S_ISREG(inode->i_mode)) { + inode->i_flags |= S_SWAPFILE; + error = inode_drain_writes(inode); + if (error) { + inode->i_flags &= ~S_SWAPFILE; + goto bad_swap; + } + } + mutex_lock(&swapon_mutex); prio = -1; if (swap_flags & SWAP_FLAG_PREFER) @@ -3185,8 +3198,6 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) atomic_inc(&proc_poll_event); wake_up_interruptible(&proc_poll_wait); - if (S_ISREG(inode->i_mode)) - inode->i_flags |= S_SWAPFILE; error = 0; goto out; bad_swap: