From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756560AbaEPM5s (ORCPT ); Fri, 16 May 2014 08:57:48 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:49535 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753352AbaEPMsV (ORCPT ); Fri, 16 May 2014 08:48:21 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Kazuya Mio" , "Theodore Ts'o" Date: Fri, 16 May 2014 13:47:20 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 01/34] ext4: FIBMAP ioctl causes BUG_ON due to handle EXT_MAX_BLOCKS In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:3db0:c181:6526:5597 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.59-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Kazuya Mio commit 4adb6ab3e0fa71363a5ef229544b2d17de6600d7 upstream. When we try to get 2^32-1 block of the file which has the extent (ee_block=2^32-2, ee_len=1) with FIBMAP ioctl, it causes BUG_ON in ext4_ext_put_gap_in_cache(). To avoid the problem, ext4_map_blocks() needs to check the file logical block number. ext4_ext_put_gap_in_cache() called via ext4_map_blocks() cannot handle 2^32-1 because the maximum file logical block number is 2^32-2. Note that ext4_ind_map_blocks() returns -EIO when the block number is invalid. So ext4_map_blocks() should also return the same errno. Signed-off-by: Kazuya Mio Signed-off-by: "Theodore Ts'o" [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -481,6 +481,11 @@ int ext4_map_blocks(handle_t *handle, st ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u," "logical block %lu\n", inode->i_ino, flags, map->m_len, (unsigned long) map->m_lblk); + + /* We can handle the block number less than EXT_MAX_BLOCKS */ + if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS)) + return -EIO; + /* * Try to see if we can get the block without requesting a new * file system block.