Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965190AbaKLDt2 (ORCPT ); Tue, 11 Nov 2014 22:49:28 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:59024 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932424AbaKLB1x (ORCPT ); Tue, 11 Nov 2014 20:27:53 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , Theodore Tso , Lukas Czerner Subject: [PATCH 3.17 162/319] ext4: fix overflow when updating superblock backups after resize Date: Wed, 12 Nov 2014 10:15:00 +0900 Message-Id: <20141112011019.478867695@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141112010952.553519040@linuxfoundation.org> References: <20141112010952.553519040@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit 9378c6768e4fca48971e7b6a9075bc006eda981d upstream. When there are no meta block groups update_backups() will compute the backup block in 32-bit arithmetics thus possibly overflowing the block number and corrupting the filesystem. OTOH filesystems without meta block groups larger than 16 TB should be rare. Fix the problem by doing the counting in 64-bit arithmetics. Coverity-id: 741252 Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Reviewed-by: Lukas Czerner Signed-off-by: Greg Kroah-Hartman --- fs/ext4/resize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1081,7 +1081,7 @@ static void update_backups(struct super_ break; if (meta_bg == 0) - backup_block = group * bpg + blk_off; + backup_block = ((ext4_fsblk_t)group) * bpg + blk_off; else backup_block = (ext4_group_first_block_no(sb, group) + ext4_bg_has_super(sb, group)); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/