Commit 7c9e69fa authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Linus Torvalds
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ext2/ext3/ext4: add block bitmap validation 



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.

[akpm@linux-foundation.org: cleanups]
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarAndreas Dilger <adilger@clusterfs.com>
Acked-by: default avatarMingming Cao <cmm@us.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 82df3973

fs/ext2/balloc.c

+44 −12
Original line number Diff line number Diff line
@@ -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)

{

fs/ext3/balloc.c

+43 −11
Original line number Diff line number Diff line
@@ -80,6 +80,14 @@ struct ext3_group_desc * ext3_get_group_desc(struct super_block * sb, 
	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()

 * @sb:			super block
@@ -93,20 +101,51 @@ 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 +1772,6 @@ 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)

{

fs/ext4/balloc.c

+47 −15
Original line number Diff line number Diff line
@@ -100,6 +100,15 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb, 
	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()

 * @sb:			super block
@@ -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;

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