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Wong" X-Patchwork-Id: 10650981 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 BC02514E2 for ; Sun, 21 Oct 2018 16:15:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A93ED287BE for ; Sun, 21 Oct 2018 16:15:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9D79C287C6; Sun, 21 Oct 2018 16:15:39 +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=-3.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E897B287C0 for ; Sun, 21 Oct 2018 16:15:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B184C6B000D; Sun, 21 Oct 2018 12:15:37 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id AC6C56B000E; Sun, 21 Oct 2018 12:15:37 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9DD546B0010; Sun, 21 Oct 2018 12:15:37 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-yw1-f72.google.com (mail-yw1-f72.google.com [209.85.161.72]) by kanga.kvack.org (Postfix) with ESMTP id 6EDE86B000D for ; Sun, 21 Oct 2018 12:15:37 -0400 (EDT) Received: by mail-yw1-f72.google.com with SMTP id b70-v6so25749245ywh.3 for ; Sun, 21 Oct 2018 09:15:37 -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:subject:from:to:cc:date :message-id:in-reply-to:references:user-agent:mime-version :content-transfer-encoding; bh=6U76j76igW5rHxBV4yEGa3iiO2lOb5rXvTc2z3yca+w=; b=XW2PQZdqUmJ9iJtmyEppk9667EabJVeXAFa51a9pS6dDNJ4iBc/zLH8bRaRAWRcrGf iFGfbUkEzuh/3T4KkQctCbZCTOgUOLzJEvL/gvjxy6a/qDpYd0iBqse5aBtmvx2sg4m5 nX97EHx0FK/Vgsg6f2MjSn7lKkV6iOYNfSiqO/wPw6nlWJxqSWZsMTZDYfxNKCFeD9OD ouw5vz80K8kfeNhRJDwmKJzBWRXeINyfpEpucK2pL1TewEJm4Lo5NscbjkJuga28PM+q 8bixYB4YEQBwI9Oed6o8WGLrBXvF3PgheWzPgxtkC2+vCaLoHTeiZU4T/LKIll/KXGpT p1Jw== X-Gm-Message-State: ABuFfohqJRj78MyM7nmLtMeKu9KC7NVYhopU5tJB8DI8dDM8stWS/Rwv vkeYXzHUpFSTtin4SWic9R6L6vhAaMQIKTaO7myCdAtJNouhec6pOTUF0JI/cJPtLsmP3qFckX0 lxcOWHwgOqgG7JLUh8F+bFjavuID1xELMzKbrzjkfYLVUmyIoI2KFckfyCUj3HzXi9g== X-Received: by 2002:a25:854e:: with SMTP id f14-v6mr19718541ybn.105.1540138537169; Sun, 21 Oct 2018 09:15:37 -0700 (PDT) X-Google-Smtp-Source: ACcGV62npDXCG9ZMOJE897EEipTOiNhrihTZtkr5SadftJGtbsz9JhdBoDG7xZrWmoDxkY+nDSmr X-Received: by 2002:a25:854e:: with SMTP id f14-v6mr19718496ybn.105.1540138536375; Sun, 21 Oct 2018 09:15:36 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1540138536; cv=none; d=google.com; s=arc-20160816; b=0T3nUGlqVwKzmc70twV5pSic8/IjdP7TF/yXgBrnowGJe/BL85QmsJPC7idtM6Q/9p 24MH+05mpEL/Dt6MxeaSieAUS5UJLlxTQa3i00rgaHwIBVW1DSkAB1uR0A1sKS4bz9u6 enh1D7Pmm9s81phlsLV9BwUNWfFWgwsdse56hdeVM0qrlWV5V/oaDO6B4HpwOh10Uf4O Gcw/PQpya/ooLXDt7wIpQfp4b5z1fyam8w9Zw3POR1j0GOYZ5ldjl93tQHFYVwNEOD6g s6FzYcYF+CUIXrYfrV3fg8TgCiEsKlkfhF4XAiDBd5Y++r43ajfhnHukidGntteeTTCg yRIA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:user-agent:references :in-reply-to:message-id:date:cc:to:from:subject:dkim-signature; bh=6U76j76igW5rHxBV4yEGa3iiO2lOb5rXvTc2z3yca+w=; b=OkhAzLr6pvD8VfiY0YJBNoZXFbPljhKFEVLCsDCC7isyg226INXZ/MZkADy6wFtqW6 hqSrPhDJwyq9HMfzfzb4baa8PRGv2bNJaclYvnqrv3ERBMl3yMnm+4Wm1zjc/mNlS+DR D7qo14JvVmDf3hYTqFXzadmcgmmHsMADMMvidGZDSQaMkHavHQONkZA3kJ/iMRm8Gs9+ htW1G3RcClJ+A5lwCxlqBTaWm4HZMljr6Pb29CePjQnr9+t7Dt3Ag3YDt2mIN+VUKsJS oeVg3wwQW4zVzRIkK++0yH9m7R+vlhAGOHxwM+XCKO3Ae7Hsvwi4sqxRwYxvZQt/Y0F/ bKCQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2018-07-02 header.b=sJiwqeH4; spf=pass (google.com: domain of darrick.wong@oracle.com designates 156.151.31.85 as permitted sender) smtp.mailfrom=darrick.wong@oracle.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=oracle.com Received: from userp2120.oracle.com (userp2120.oracle.com. [156.151.31.85]) by mx.google.com with ESMTPS id 131-v6si12902646ybk.15.2018.10.21.09.15.36 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 21 Oct 2018 09:15:36 -0700 (PDT) Received-SPF: pass (google.com: domain of darrick.wong@oracle.com designates 156.151.31.85 as permitted sender) client-ip=156.151.31.85; Authentication-Results: mx.google.com; dkim=pass header.i=@oracle.com header.s=corp-2018-07-02 header.b=sJiwqeH4; spf=pass (google.com: domain of darrick.wong@oracle.com designates 156.151.31.85 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 (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w9LGEbqS106972; Sun, 21 Oct 2018 16:15:34 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=6U76j76igW5rHxBV4yEGa3iiO2lOb5rXvTc2z3yca+w=; b=sJiwqeH4X6gEw0lXCFlzzmk9BQSeC7DC/DPG2XKYEwNDCJumhFYBrMWydRzex27pMbjV 33x0Ux4eT4dk//SgW5BAuGHL0SzHb7Ieb3cx/7m8nngYpjO0Mh1Lc9K4he4z3SDfbPec 4+PgsJ1Hp8eOiOStSKoxD18Hfg0FDZwpMqKYzQfyB3okDiBLJbjGAXINPSCQ9+1yaw50 DOgko2nCl5xsn7L+luOOeqzn/eC1QrxE0hpbwEsTFBthjnOhFv2XBEaHZpnCJj1FsT5A sWMnIlyLSlOrI3NnZUEEfW4PlLGqKBA68JxwtgQVxMnNbp7ZA6SrL5OPF+rtaHBZCyV/ 7Q== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by userp2120.oracle.com with ESMTP id 2n7w0qaxh1-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 21 Oct 2018 16:15:34 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w9LGFXqi003693 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 21 Oct 2018 16:15:33 GMT Received: from abhmp0015.oracle.com (abhmp0015.oracle.com [141.146.116.21]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w9LGFWng018862; Sun, 21 Oct 2018 16:15:33 GMT Received: from localhost (/10.159.225.70) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sun, 21 Oct 2018 09:15:32 -0700 Subject: [PATCH 04/28] vfs: strengthen checking of file range inputs to generic_remap_checks From: "Darrick J. Wong" To: david@fromorbit.com, darrick.wong@oracle.com Cc: sandeen@redhat.com, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, Amir Goldstein , linux-unionfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig , ocfs2-devel@oss.oracle.com Date: Sun, 21 Oct 2018 09:15:30 -0700 Message-ID: <154013853068.29026.16132846055457280127.stgit@magnolia> In-Reply-To: <154013850285.29026.16168387526580596209.stgit@magnolia> References: <154013850285.29026.16168387526580596209.stgit@magnolia> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9053 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810210151 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: X-Virus-Scanned: ClamAV using ClamSMTP From: Darrick J. Wong File range remapping, if allowed to run past the destination file's EOF, is an optimization on a regular file write. Regular file writes that extend the file length are subject to various constraints which are not checked by range cloning. This is a correctness problem because we're never allowed to touch ranges that the page cache can't support (s_maxbytes); we're not supposed to deal with large offsets (MAX_NON_LFS) if O_LARGEFILE isn't set; and we must obey resource limits (RLIMIT_FSIZE). Therefore, add these checks to the new generic_remap_checks function so that we curtail unexpected behavior. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein Reviewed-by: Christoph Hellwig --- mm/filemap.c | 84 ++++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 52 insertions(+), 32 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index 47e6bfd45a91..84b7301e41a0 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2915,6 +2915,42 @@ struct page *read_cache_page_gfp(struct address_space *mapping, } EXPORT_SYMBOL(read_cache_page_gfp); +/* + * Don't operate on ranges the page cache doesn't support, and don't exceed the + * LFS limits. If pos is under the limit it becomes a short access. If it + * exceeds the limit we return -EFBIG. + */ +static int generic_access_check_limits(struct file *file, loff_t pos, + loff_t *count) +{ + struct inode *inode = file->f_mapping->host; + loff_t max_size = inode->i_sb->s_maxbytes; + + if (!(file->f_flags & O_LARGEFILE)) + max_size = MAX_NON_LFS; + + if (unlikely(pos >= max_size)) + return -EFBIG; + *count = min(*count, max_size - pos); + return 0; +} + +static int generic_write_check_limits(struct file *file, loff_t pos, + loff_t *count) +{ + loff_t limit = rlimit(RLIMIT_FSIZE); + + if (limit != RLIM_INFINITY) { + if (pos >= limit) { + send_sig(SIGXFSZ, current, 0); + return -EFBIG; + } + *count = min(*count, limit - pos); + } + + return generic_access_check_limits(file, pos, count); +} + /* * Performs necessary checks before doing a write * @@ -2926,8 +2962,8 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; - unsigned long limit = rlimit(RLIMIT_FSIZE); - loff_t pos; + loff_t count; + int ret; if (!iov_iter_count(from)) return 0; @@ -2936,40 +2972,15 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) if (iocb->ki_flags & IOCB_APPEND) iocb->ki_pos = i_size_read(inode); - pos = iocb->ki_pos; - if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT)) return -EINVAL; - if (limit != RLIM_INFINITY) { - if (iocb->ki_pos >= limit) { - send_sig(SIGXFSZ, current, 0); - return -EFBIG; - } - iov_iter_truncate(from, limit - (unsigned long)pos); - } - - /* - * LFS rule - */ - if (unlikely(pos + iov_iter_count(from) > MAX_NON_LFS && - !(file->f_flags & O_LARGEFILE))) { - if (pos >= MAX_NON_LFS) - return -EFBIG; - iov_iter_truncate(from, MAX_NON_LFS - (unsigned long)pos); - } - - /* - * Are we about to exceed the fs block limit ? - * - * If we have written data it becomes a short write. If we have - * exceeded without writing data we send a signal and return EFBIG. - * Linus frestrict idea will clean these up nicely.. - */ - if (unlikely(pos >= inode->i_sb->s_maxbytes)) - return -EFBIG; + count = iov_iter_count(from); + ret = generic_write_check_limits(file, iocb->ki_pos, &count); + if (ret) + return ret; - iov_iter_truncate(from, inode->i_sb->s_maxbytes - pos); + iov_iter_truncate(from, count); return iov_iter_count(from); } EXPORT_SYMBOL(generic_write_checks); @@ -2991,6 +3002,7 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, uint64_t bcount; loff_t size_in, size_out; loff_t bs = inode_out->i_sb->s_blocksize; + int ret; /* The start of both ranges must be aligned to an fs block. */ if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_out, bs)) @@ -3014,6 +3026,14 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, return -EINVAL; count = min(count, size_in - (uint64_t)pos_in); + ret = generic_access_check_limits(file_in, pos_in, &count); + if (ret) + return ret; + + ret = generic_write_check_limits(file_out, pos_out, &count); + if (ret) + return ret; + /* * If the user wanted us to link to the infile's EOF, round up to the * next block boundary for this check.