From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Changman Lee , Jan Kara , Jaegeuk Kim Subject: [PATCH 3.17 16/73] f2fs: fix possible data corruption in f2fs_write_begin() Date: Tue, 6 Jan 2015 18:15:37 -0800 Message-Id: <20150107021558.020815842@linuxfoundation.org> In-Reply-To: <20150107021557.521276020@linuxfoundation.org> References: <20150107021557.521276020@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit 9234f3190bf8b25b11b105191d408ac50a107948 upstream. f2fs_write_begin() doesn't initialize the 'dn' variable if the inode has inline data. However it uses its contents to decide whether it should just zero out the page or load data to it. Thus if we are unlucky we can zero out page contents instead of loading inline data into a page. CC: Changman Lee Signed-off-by: Jan Kara Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/data.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1002,21 +1002,19 @@ inline_data: goto out; } - if (dn.data_blkaddr == NEW_ADDR) { + if (f2fs_has_inline_data(inode)) { + err = f2fs_read_inline_data(inode, page); + if (err) { + page_cache_release(page); + goto fail; + } + } else if (dn.data_blkaddr == NEW_ADDR) { zero_user_segment(page, 0, PAGE_CACHE_SIZE); } else { - if (f2fs_has_inline_data(inode)) { - err = f2fs_read_inline_data(inode, page); - if (err) { - page_cache_release(page); - goto fail; - } - } else { - err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr, - READ_SYNC); - if (err) - goto fail; - } + err = f2fs_submit_page_bio(sbi, page, dn.data_blkaddr, + READ_SYNC); + if (err) + goto fail; lock_page(page); if (unlikely(!PageUptodate(page))) {