From linux-kernel-owner+willy=40w.ods.org-S261207AbUKHUAL@vger.kernel.org Mon Nov 8 21:03:21 2004 Return-Path: Received: from vger.kernel.org (vger.kernel.org [12.107.209.244]) by mail.w.ods.org (8.12.9/8.12.1) with ESMTP id iA8K3Iac000474 for ; Mon, 8 Nov 2004 21:03:19 +0100 (CET) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261207AbUKHUAL (ORCPT ); Mon, 8 Nov 2004 15:00:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261211AbUKHUAL (ORCPT ); Mon, 8 Nov 2004 15:00:11 -0500 Received: from hera.cwi.nl ([192.16.191.8]:44242 "EHLO hera.cwi.nl") by vger.kernel.org with ESMTP id S261207AbUKHT7n (ORCPT ); Mon, 8 Nov 2004 14:59:43 -0500 Received: from apps.cwi.nl (apps.cwi.nl [192.16.191.34]) by hera.cwi.nl with ESMTP id iA8JxaCf009567 for ; Mon, 8 Nov 2004 20:59:36 +0100 (MET) Received: (from aeb@localhost) by apps.cwi.nl (8.11.7p1+Sun/8.12.2) id iA8JxZT00364; Mon, 8 Nov 2004 20:59:35 +0100 (MET) Date: Mon, 8 Nov 2004 20:59:35 +0100 From: Andries Brouwer To: torvalds@osdl.org, akpm@osdl.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH] don't divide by 0 when trying to mount ext3 Message-ID: <20041108195934.GA29981@apps.cwi.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org Status: RO Content-Length: 2712 Lines: 77 Not surprisingly, the ext3 code crashes in the same way the ext2 code does when dividing by zero. diff -uprN -X /linux/dontdiff a/fs/ext3/super.c b/fs/ext3/super.c --- a/fs/ext3/super.c 2004-10-30 21:44:02.000000000 +0200 +++ b/fs/ext3/super.c 2004-11-08 20:55:30.000000000 +0100 @@ -1259,13 +1259,8 @@ static int ext3_fill_super (struct super es = (struct ext3_super_block *) (((char *)bh->b_data) + offset); sbi->s_es = es; sb->s_magic = le16_to_cpu(es->s_magic); - if (sb->s_magic != EXT3_SUPER_MAGIC) { - if (!silent) - printk(KERN_ERR - "VFS: Can't find ext3 filesystem on dev %s.\n", - sb->s_id); - goto failed_mount; - } + if (sb->s_magic != EXT3_SUPER_MAGIC) + goto cantfind_ext3; /* Set defaults before we parse the mount options */ def_mount_opts = le32_to_cpu(es->s_default_mount_opts); @@ -1397,8 +1392,13 @@ static int ext3_fill_super (struct super sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group); sbi->s_frags_per_group = le32_to_cpu(es->s_frags_per_group); sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group); + if (EXT3_INODE_SIZE(sb) == 0) + goto cantfind_ext3; sbi->s_inodes_per_block = blocksize / EXT3_INODE_SIZE(sb); - sbi->s_itb_per_group = sbi->s_inodes_per_group /sbi->s_inodes_per_block; + if (sbi->s_inodes_per_block == 0) + goto cantfind_ext3; + sbi->s_itb_per_group = sbi->s_inodes_per_group / + sbi->s_inodes_per_block; sbi->s_desc_per_block = blocksize / sizeof(struct ext3_group_desc); sbi->s_sbh = bh; sbi->s_mount_state = le16_to_cpu(es->s_state); @@ -1427,6 +1427,8 @@ static int ext3_fill_super (struct super goto failed_mount; } + if (EXT3_BLOCKS_PER_GROUP(sb) == 0) + goto cantfind_ext3; sbi->s_groups_count = (le32_to_cpu(es->s_blocks_count) - le32_to_cpu(es->s_first_data_block) + EXT3_BLOCKS_PER_GROUP(sb) - 1) / @@ -1579,6 +1581,12 @@ static int ext3_fill_super (struct super return 0; +cantfind_ext3: + if (!silent) + printk(KERN_ERR "VFS: Can't find ext3 filesystem on dev %s.\n", + sb->s_id); + goto failed_mount; + failed_mount3: journal_destroy(sbi->s_journal); failed_mount2: @@ -1588,10 +1596,8 @@ failed_mount2: kfree(sbi->s_group_desc); failed_mount: #ifdef CONFIG_QUOTA - for (i = 0; i < MAXQUOTAS; i++) { - if (sbi->s_qf_names[i]) - kfree(sbi->s_qf_names[i]); - } + for (i = 0; i < MAXQUOTAS; i++) + kfree(sbi->s_qf_names[i]); #endif ext3_blkdev_remove(sbi); brelse(bh); - 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/