From patchwork Mon Dec 3 08:34:09 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Chinner X-Patchwork-Id: 1006704 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-cifs-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=fromorbit.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 437db94FJKz9sBh for ; Mon, 3 Dec 2018 19:34:45 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725913AbeLCIeb (ORCPT ); Mon, 3 Dec 2018 03:34:31 -0500 Received: from ipmailnode02.adl6.internode.on.net ([150.101.137.148]:39077 "EHLO ipmailnode02.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725830AbeLCIeb (ORCPT ); Mon, 3 Dec 2018 03:34:31 -0500 Received: from ppp59-167-129-252.static.internode.on.net (HELO dastard) ([59.167.129.252]) by ipmail02.adl6.internode.on.net with ESMTP; 03 Dec 2018 19:04:19 +1030 Received: from discord.disaster.area ([192.168.1.111]) by dastard with esmtp (Exim 4.80) (envelope-from ) id 1gTjgJ-0003PU-11; Mon, 03 Dec 2018 19:34:19 +1100 Received: from dave by discord.disaster.area with local (Exim 4.91) (envelope-from ) id 1gTjgI-000064-WC; Mon, 03 Dec 2018 19:34:19 +1100 From: Dave Chinner To: linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org Cc: olga.kornievskaia@gmail.com, linux-nfs@vger.kernel.org, linux-unionfs@vger.kernel.org, ceph-devel@vger.kernel.org, linux-cifs@vger.kernel.org Subject: [PATCH 04/11] vfs: add missing checks to copy_file_range Date: Mon, 3 Dec 2018 19:34:09 +1100 Message-Id: <20181203083416.28978-5-david@fromorbit.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181203083416.28978-1-david@fromorbit.com> References: <20181203083416.28978-1-david@fromorbit.com> MIME-Version: 1.0 Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org From: Dave Chinner Like the clone and dedupe interfaces we've recently fixed, the copy_file_range() implementation is missing basic sanity, limits and boundary condition tests on the parameters that are passed to it from userspace. Create a new "generic_copy_file_checks()" function modelled on the generic_remap_checks() function to provide this missing functionality. Signed-off-by: Dave Chinner Reviewed-by: Amir Goldstein --- fs/read_write.c | 27 ++++++------------ include/linux/fs.h | 3 ++ mm/filemap.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 81 insertions(+), 18 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index 44339b44accc..69809345977e 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1578,7 +1578,7 @@ static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in, return file_out->f_op->copy_file_range(file_in, pos_in, file_out, pos_out, len, flags); - return generic_copy_file_range(file_in, &pos_in, file_out, &pos_out, + return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len, flags); } @@ -1598,10 +1598,14 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (flags != 0) return -EINVAL; - if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) - return -EISDIR; - if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) - return -EINVAL; + /* this could be relaxed once a method supports cross-fs copies */ + if (inode_in->i_sb != inode_out->i_sb) + return -EXDEV; + + ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len, + flags); + if (ret < 0) + return ret; ret = rw_verify_area(READ, file_in, &pos_in, len); if (unlikely(ret)) @@ -1611,22 +1615,9 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, if (unlikely(ret)) return ret; - if (!(file_in->f_mode & FMODE_READ) || - !(file_out->f_mode & FMODE_WRITE) || - (file_out->f_flags & O_APPEND)) - return -EBADF; - - /* this could be relaxed once a method supports cross-fs copies */ - if (inode_in->i_sb != inode_out->i_sb) - return -EXDEV; - if (len == 0) return 0; - /* If the source range crosses EOF, fail the copy */ - if (pos_in >= i_size(inode_in) || pos_in + len > i_size(inode_in)) - return -EINVAL; - file_start_write(file_out); /* diff --git a/include/linux/fs.h b/include/linux/fs.h index a4478764cf63..0d9d2d93d4df 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3022,6 +3022,9 @@ extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *); extern int generic_remap_checks(struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, loff_t *count, unsigned int remap_flags); +extern int generic_copy_file_checks(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + size_t *count, unsigned int flags); extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *); extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *); extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *); diff --git a/mm/filemap.c b/mm/filemap.c index 81adec8ee02c..0a170425935b 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2975,6 +2975,75 @@ int generic_remap_checks(struct file *file_in, loff_t pos_in, return 0; } + +/* + * Performs necessary checks before doing a file copy + * + * Can adjust amount of bytes to copy + * Returns appropriate error code that caller should return or + * zero in case the copy should be allowed. + */ +int generic_copy_file_checks(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + size_t *req_count, unsigned int flags) +{ + struct inode *inode_in = file_inode(file_in); + struct inode *inode_out = file_inode(file_out); + uint64_t count = *req_count; + uint64_t bcount; + loff_t size_in, size_out; + loff_t bs = inode_out->i_sb->s_blocksize; + int ret; + + /* Don't touch certain kinds of inodes */ + if (IS_IMMUTABLE(inode_out)) + return -EPERM; + + if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out)) + return -ETXTBSY; + + /* Don't copy dirs, pipes, sockets... */ + if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode)) + return -EISDIR; + if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) + return -EINVAL; + + if (!(file_in->f_mode & FMODE_READ) || + !(file_out->f_mode & FMODE_WRITE) || + (file_out->f_flags & O_APPEND)) + return -EBADF; + + /* Ensure offsets don't wrap. */ + if (pos_in + count < pos_in || pos_out + count < pos_out) + return -EOVERFLOW; + + size_in = i_size_read(inode_in); + size_out = i_size_read(inode_out); + + /* If the source range crosses EOF, fail the copy */ + if (pos_in >= size_in) + return -EINVAL; + if (pos_in + count > size_in) + return -EINVAL; + + 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; + + /* Don't allow overlapped copying within the same file. */ + if (inode_in == inode_out && + pos_out + count > pos_in && + pos_out < pos_in + count) + return -EINVAL; + + *req_count = count; + return 0; +} + int pagecache_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata)