From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753780AbbHBAL6 (ORCPT ); Sat, 1 Aug 2015 20:11:58 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36141 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751958AbbHBAJu (ORCPT ); Sat, 1 Aug 2015 20:09:50 -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, "Theodore Ts'o" , "Eryu Guan" Date: Sun, 02 Aug 2015 01:02:37 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 094/164] ext4: check for zero length extent explicitly In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 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 3.2.70-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Eryu Guan commit 2f974865ffdfe7b9f46a9940836c8b167342563d upstream. The following commit introduced a bug when checking for zero length extent 5946d08 ext4: check for overlapping extents in ext4_valid_extent_entries() Zero length extent could pass the check if lblock is zero. Adding the explicit check for zero length back. Signed-off-by: Eryu Guan Signed-off-by: Theodore Ts'o Signed-off-by: Ben Hutchings --- fs/ext4/extents.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -321,7 +321,7 @@ static int ext4_valid_extent(struct inod ext4_lblk_t lblock = le32_to_cpu(ext->ee_block); ext4_lblk_t last = lblock + len - 1; - if (lblock > last) + if (len == 0 || lblock > last) return 0; return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len); }