From: "Aneesh Kumar K.V" Subject: [PATCH] ext2/ext3/ext4: Add block bitmap validation Date: Fri, 3 Aug 2007 12:40:50 +0530 Message-ID: <11861250501999-git-send-email-aneesh.kumar@linux.vnet.ibm.com> Cc: linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" , Andreas Dilger To: cmm@us.ibm.com Return-path: Received: from ausmtp04.au.ibm.com ([202.81.18.152]:60782 "EHLO ausmtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758290AbXHCHMC (ORCPT ); Fri, 3 Aug 2007 03:12:02 -0400 Received: from sd0109e.au.ibm.com (d23rh905.au.ibm.com [202.81.18.225]) by ausmtp04.au.ibm.com (8.13.8/8.13.8) with ESMTP id l737E1jQ309552 for ; Fri, 3 Aug 2007 17:14:13 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.250.237]) by sd0109e.au.ibm.com (8.13.8/8.13.8/NCO v8.4) with ESMTP id l737ETGs163100 for ; Fri, 3 Aug 2007 17:14:29 +1000 Received: from d23av04.au.ibm.com (loopback [127.0.0.1]) by d23av04.au.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l737AtqK021815 for ; Fri, 3 Aug 2007 17:10:56 +1000 Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org When a new block bitmap is read from disk in read_block_bitmap() there are a few bits that should ALWAYS be set. In particular, the blocks given by ext4_blk_bitmap, ext4_inode_bitmap and ext4_inode_table. Validate the block bitmap against these blocks. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Andreas Dilger --- fs/ext2/balloc.c | 56 ++++++++++++++++++++++++++++++++++++++---------- fs/ext3/balloc.c | 53 ++++++++++++++++++++++++++++++++++++--------- fs/ext4/balloc.c | 62 ++++++++++++++++++++++++++++++++++++++++------------- 3 files changed, 133 insertions(+), 38 deletions(-) diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index baf71dd..917a443 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -69,6 +69,14 @@ struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb, return desc + offset; } +static inline int +block_in_use(unsigned long block, struct super_block *sb, unsigned char *map) +{ + return ext2_test_bit ((block - + le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block)) % + EXT2_BLOCKS_PER_GROUP(sb), map); +} + /* * Read the bitmap for a given block_group, reading into the specified * slot in the superblock's bitmap cache. @@ -78,20 +86,51 @@ struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb, static struct buffer_head * read_block_bitmap(struct super_block *sb, unsigned int block_group) { + int i; struct ext2_group_desc * desc; struct buffer_head * bh = NULL; - + unsigned int bitmap_blk; + desc = ext2_get_group_desc (sb, block_group, NULL); if (!desc) - goto error_out; - bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap)); + return NULL; + bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); + bh = sb_bread(sb, bitmap_blk); if (!bh) - ext2_error (sb, "read_block_bitmap", + ext2_error (sb, __FUNCTION__, "Cannot read block bitmap - " "block_group = %d, block_bitmap = %u", block_group, le32_to_cpu(desc->bg_block_bitmap)); -error_out: + + /* check whether block bitmap block number is set */ + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + /* check whether the inode bitmap block number is set */ + bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap); + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + /* check whether the inode table block number is set */ + bitmap_blk = le32_to_cpu(desc->bg_inode_table); + for (i = 0; i < EXT2_SB(sb)->s_itb_per_group; i++, bitmap_blk++) { + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + } + return bh; + +error_out: + brelse(bh); + ext2_error(sb, __FUNCTION__, + "Invalid block bitmap - " + "block_group = %d, block = %u", + block_group, bitmap_blk); + return NULL; } /* @@ -583,13 +622,6 @@ unsigned long ext2_count_free_blocks (struct super_block * sb) #endif } -static inline int -block_in_use(unsigned long block, struct super_block *sb, unsigned char *map) -{ - return ext2_test_bit ((block - - le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block)) % - EXT2_BLOCKS_PER_GROUP(sb), map); -} static inline int test_root(int a, int b) { diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c index ca8aee6..b44c76f 100644 --- a/fs/ext3/balloc.c +++ b/fs/ext3/balloc.c @@ -79,6 +79,13 @@ struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb, *bh = sbi->s_group_desc[group_desc]; return desc + offset; } +static inline int +block_in_use(ext3_fsblk_t block, struct super_block *sb, unsigned char *map) +{ + return ext3_test_bit ((block - + le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) % + EXT3_BLOCKS_PER_GROUP(sb), map); +} /** * read_block_bitmap() @@ -93,20 +100,51 @@ struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb, static struct buffer_head * read_block_bitmap(struct super_block *sb, unsigned int block_group) { + int i; struct ext3_group_desc * desc; struct buffer_head * bh = NULL; + ext3_fsblk_t bitmap_blk; desc = ext3_get_group_desc (sb, block_group, NULL); if (!desc) - goto error_out; - bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap)); + return NULL; + bitmap_blk = le32_to_cpu(desc->bg_block_bitmap); + bh = sb_bread(sb, bitmap_blk); if (!bh) - ext3_error (sb, "read_block_bitmap", + ext3_error (sb, __FUNCTION__, "Cannot read block bitmap - " "block_group = %d, block_bitmap = %u", block_group, le32_to_cpu(desc->bg_block_bitmap)); -error_out: + + /* check whether block bitmap block number is set */ + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + /* check whether the inode bitmap block number is set */ + bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap); + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + /* check whether the inode table block number is set */ + bitmap_blk = le32_to_cpu(desc->bg_inode_table); + for (i = 0; i < EXT3_SB(sb)->s_itb_per_group; i++, bitmap_blk++) { + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + } + return bh; + +error_out: + brelse(bh); + ext3_error(sb, __FUNCTION__, + "Invalid block bitmap - " + "block_group = %d, block = %lu", + block_group, bitmap_blk); + return NULL; } /* * The reservation window structure operations @@ -1733,13 +1771,6 @@ ext3_fsblk_t ext3_count_free_blocks(struct super_block *sb) #endif } -static inline int -block_in_use(ext3_fsblk_t block, struct super_block *sb, unsigned char *map) -{ - return ext3_test_bit ((block - - le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block)) % - EXT3_BLOCKS_PER_GROUP(sb), map); -} static inline int test_root(int a, int b) { diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 3b64bb1..7d58f12 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -99,6 +99,15 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb, *bh = sbi->s_group_desc[group_desc]; return desc; } +static inline int +block_in_use(ext4_fsblk_t block, struct super_block *sb, unsigned char *map) +{ + ext4_grpblk_t offset; + + ext4_get_group_no_and_offset(sb, block, NULL, &offset); + return ext4_test_bit (offset, map); +} + /** * read_block_bitmap() @@ -113,21 +122,53 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb, static struct buffer_head * read_block_bitmap(struct super_block *sb, unsigned int block_group) { + int i; struct ext4_group_desc * desc; struct buffer_head * bh = NULL; + ext4_fsblk_t bitmap_blk; desc = ext4_get_group_desc (sb, block_group, NULL); if (!desc) - goto error_out; - bh = sb_bread(sb, ext4_block_bitmap(sb, desc)); + return NULL; + bitmap_blk = ext4_block_bitmap(sb, desc); + bh = sb_bread(sb, bitmap_blk); if (!bh) - ext4_error (sb, "read_block_bitmap", + ext4_error (sb, __FUNCTION__, "Cannot read block bitmap - " "block_group = %d, block_bitmap = %llu", - block_group, - ext4_block_bitmap(sb, desc)); -error_out: + block_group, bitmap_blk); + + /* check whether block bitmap block number is set */ + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + + /* check whether the inode bitmap block number is set */ + bitmap_blk = ext4_inode_bitmap(sb, desc); + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + /* check whether the inode table block number is set */ + bitmap_blk = ext4_inode_table(sb, desc); + for (i = 0; i < EXT4_SB(sb)->s_itb_per_group; i++, bitmap_blk++) { + if (!block_in_use(bitmap_blk, sb, bh->b_data)) { + /* bad block bitmap */ + goto error_out; + } + } + return bh; + +error_out: + brelse(bh); + ext4_error(sb, __FUNCTION__, + "Invalid block bitmap - " + "block_group = %d, block = %llu", + block_group, bitmap_blk); + return NULL; + } /* * The reservation window structure operations @@ -1747,15 +1788,6 @@ ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb) #endif } -static inline int -block_in_use(ext4_fsblk_t block, struct super_block *sb, unsigned char *map) -{ - ext4_grpblk_t offset; - - ext4_get_group_no_and_offset(sb, block, NULL, &offset); - return ext4_test_bit (offset, map); -} - static inline int test_root(int a, int b) { int num = b; -- 1.5.3.rc2.22.g69a9b-dirty