From patchwork Wed Dec 18 13:09:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Gruenbacher X-Patchwork-Id: 11300681 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3AE1E139A for ; Wed, 18 Dec 2019 13:09:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 050212176D for ; Wed, 18 Dec 2019 13:09:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YcdlH4pD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726969AbfLRNJ5 (ORCPT ); Wed, 18 Dec 2019 08:09:57 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:31435 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726902AbfLRNJy (ORCPT ); Wed, 18 Dec 2019 08:09:54 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1576674592; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=g5Ox4SHhc2xo2sY+PCKlmfIwG02oA4188ugvQugMGko=; b=YcdlH4pDb90tH1AU8byozWMg8zmiplQG8bqmvUWb1rjT4kLbsIN/pMOimhx0kkIqJ1/BGZ gsAM67IymtKinjM5CaNfDbbFGRArDCRRaDZoqqHOtFMI6cn24d/MkwCgHZqln8UcN4iX8S u9wZnhLIggIS4ATlmAznPf505Mct7P4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-34-RjePyPrbN4iiCFi_W_pbZA-1; Wed, 18 Dec 2019 08:09:51 -0500 X-MC-Unique: RjePyPrbN4iiCFi_W_pbZA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DB92A10054E3; Wed, 18 Dec 2019 13:09:46 +0000 (UTC) Received: from max.com (ovpn-204-101.brq.redhat.com [10.40.204.101]) by smtp.corp.redhat.com (Postfix) with ESMTP id E01D760C18; Wed, 18 Dec 2019 13:09:37 +0000 (UTC) From: Andreas Gruenbacher To: "Darrick J. Wong" Cc: Andreas Gruenbacher , Alexander Viro , Christoph Hellwig , Linus Torvalds , linux-kernel@vger.kernel.org, Jeff Layton , Sage Weil , Ilya Dryomov , "Theodore Ts'o" , Andreas Dilger , Jaegeuk Kim , Chao Yu , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Richard Weinberger , Artem Bityutskiy , Adrian Hunter , ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org, Chris Mason , Josef Bacik , David Sterba , linux-btrfs@vger.kernel.org, Jan Kara Subject: [PATCH v3] fs: Fix page_mkwrite off-by-one errors Date: Wed, 18 Dec 2019 14:09:35 +0100 Message-Id: <20191218130935.32402-1-agruenba@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Hi Darrick, can this fix go in via the xfs tree? Thanks, Andreas Reviewed-by: Jan Kara Acked-by: Theodore Ts'o Acked-by: Chao Yu --- The check in block_page_mkwrite that is meant to determine whether an offset is within the inode size is off by one. This bug has been copied into iomap_page_mkwrite and several filesystems (ubifs, ext4, f2fs, ceph). Fix that by introducing a new page_mkwrite_check_truncate helper that checks for truncate and computes the bytes in the page up to EOF. Use the helper in the above mentioned filesystems. In addition, use the new helper in btrfs as well. Signed-off-by: Andreas Gruenbacher Acked-by: David Sterba (btrfs part) Acked-by: Richard Weinberger (ubifs part) --- fs/btrfs/inode.c | 15 ++++----------- fs/buffer.c | 16 +++------------- fs/ceph/addr.c | 2 +- fs/ext4/inode.c | 14 ++++---------- fs/f2fs/file.c | 19 +++++++------------ fs/iomap/buffered-io.c | 18 +++++------------- fs/ubifs/file.c | 3 +-- include/linux/pagemap.h | 28 ++++++++++++++++++++++++++++ 8 files changed, 53 insertions(+), 62 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 56032c518b26..86c6fcd8139d 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9016,13 +9016,11 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ again: lock_page(page); - size = i_size_read(inode); - if ((page->mapping != inode->i_mapping) || - (page_start >= size)) { - /* page got truncated out from underneath us */ + ret2 = page_mkwrite_check_truncate(page, inode); + if (ret2 < 0) goto out_unlock; - } + zero_start = ret2; wait_on_page_writeback(page); lock_extent_bits(io_tree, page_start, page_end, &cached_state); @@ -9043,6 +9041,7 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) goto again; } + size = i_size_read(inode); if (page->index == ((size - 1) >> PAGE_SHIFT)) { reserved_space = round_up(size - page_start, fs_info->sectorsize); @@ -9075,12 +9074,6 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) } ret2 = 0; - /* page is wholly or partially inside EOF */ - if (page_start + PAGE_SIZE > size) - zero_start = offset_in_page(size); - else - zero_start = PAGE_SIZE; - if (zero_start != PAGE_SIZE) { kaddr = kmap(page); memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start); diff --git a/fs/buffer.c b/fs/buffer.c index d8c7242426bb..53aabde57ca7 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2499,23 +2499,13 @@ int block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, struct page *page = vmf->page; struct inode *inode = file_inode(vma->vm_file); unsigned long end; - loff_t size; int ret; lock_page(page); - size = i_size_read(inode); - if ((page->mapping != inode->i_mapping) || - (page_offset(page) > size)) { - /* We overload EFAULT to mean page got truncated */ - ret = -EFAULT; + ret = page_mkwrite_check_truncate(page, inode); + if (ret < 0) goto out_unlock; - } - - /* page is wholly or partially inside EOF */ - if (((page->index + 1) << PAGE_SHIFT) > size) - end = size & ~PAGE_MASK; - else - end = PAGE_SIZE; + end = ret; ret = __block_write_begin(page, 0, end, get_block); if (!ret) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 7ab616601141..ef958aa4adb4 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -1575,7 +1575,7 @@ static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf) do { lock_page(page); - if ((off > size) || (page->mapping != inode->i_mapping)) { + if (page_mkwrite_check_truncate(page, inode) < 0) { unlock_page(page); ret = VM_FAULT_NOPAGE; break; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 28f28de0c1b6..51ab1d2cac80 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5871,7 +5871,6 @@ vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; struct page *page = vmf->page; - loff_t size; unsigned long len; int err; vm_fault_t ret; @@ -5907,18 +5906,13 @@ vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf) } lock_page(page); - size = i_size_read(inode); - /* Page got truncated from under us? */ - if (page->mapping != mapping || page_offset(page) > size) { + err = page_mkwrite_check_truncate(page, inode); + if (err < 0) { unlock_page(page); - ret = VM_FAULT_NOPAGE; - goto out; + goto out_ret; } + len = err; - if (page->index == size >> PAGE_SHIFT) - len = size & ~PAGE_MASK; - else - len = PAGE_SIZE; /* * Return if we have all the buffers mapped. This avoids the need to do * journal_start/journal_stop which can block and take a long time diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 85af112e868d..0e77b2e6f873 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -51,7 +51,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) struct inode *inode = file_inode(vmf->vma->vm_file); struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct dnode_of_data dn = { .node_changed = false }; - int err; + int offset, err; if (unlikely(f2fs_cp_error(sbi))) { err = -EIO; @@ -70,13 +70,14 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) file_update_time(vmf->vma->vm_file); down_read(&F2FS_I(inode)->i_mmap_sem); lock_page(page); - if (unlikely(page->mapping != inode->i_mapping || - page_offset(page) > i_size_read(inode) || - !PageUptodate(page))) { + err = -EFAULT; + if (likely(PageUptodate(page))) + err = page_mkwrite_check_truncate(page, inode); + if (unlikely(err < 0)) { unlock_page(page); - err = -EFAULT; goto out_sem; } + offset = err; /* block allocation */ __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true); @@ -101,14 +102,8 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf) if (PageMappedToDisk(page)) goto out_sem; - /* page is wholly or partially inside EOF */ - if (((loff_t)(page->index + 1) << PAGE_SHIFT) > - i_size_read(inode)) { - loff_t offset; - - offset = i_size_read(inode) & ~PAGE_MASK; + if (offset != PAGE_SIZE) zero_user_segment(page, offset, PAGE_SIZE); - } set_page_dirty(page); if (!PageUptodate(page)) SetPageUptodate(page); diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index d33c7bc5ee92..1aaf157fd6e9 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1062,24 +1062,16 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops) struct page *page = vmf->page; struct inode *inode = file_inode(vmf->vma->vm_file); unsigned long length; - loff_t offset, size; + loff_t offset; ssize_t ret; lock_page(page); - size = i_size_read(inode); - offset = page_offset(page); - if (page->mapping != inode->i_mapping || offset > size) { - /* We overload EFAULT to mean page got truncated */ - ret = -EFAULT; + ret = page_mkwrite_check_truncate(page, inode); + if (ret < 0) goto out_unlock; - } - - /* page is wholly or partially inside EOF */ - if (offset > size - PAGE_SIZE) - length = offset_in_page(size); - else - length = PAGE_SIZE; + length = ret; + offset = page_offset(page); while (length > 0) { ret = iomap_apply(inode, offset, length, IOMAP_WRITE | IOMAP_FAULT, ops, page, diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index cd52585c8f4f..91f7a1f2db0d 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -1563,8 +1563,7 @@ static vm_fault_t ubifs_vm_page_mkwrite(struct vm_fault *vmf) } lock_page(page); - if (unlikely(page->mapping != inode->i_mapping || - page_offset(page) > i_size_read(inode))) { + if (unlikely(page_mkwrite_check_truncate(page, inode) < 0)) { /* Page got truncated out from underneath us */ goto sigbus; } diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 37a4d9e32cd3..ccb14b6a16b5 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -636,4 +636,32 @@ static inline unsigned long dir_pages(struct inode *inode) PAGE_SHIFT; } +/** + * page_mkwrite_check_truncate - check if page was truncated + * @page: the page to check + * @inode: the inode to check the page against + * + * Returns the number of bytes in the page up to EOF, + * or -EFAULT if the page was truncated. + */ +static inline int page_mkwrite_check_truncate(struct page *page, + struct inode *inode) +{ + loff_t size = i_size_read(inode); + pgoff_t index = size >> PAGE_SHIFT; + int offset = offset_in_page(size); + + if (page->mapping != inode->i_mapping) + return -EFAULT; + + /* page is wholly inside EOF */ + if (page->index < index) + return PAGE_SIZE; + /* page is wholly past EOF */ + if (page->index > index || !offset) + return -EFAULT; + /* page is partially inside EOF */ + return offset; +} + #endif /* _LINUX_PAGEMAP_H */