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Commit ac48bb9b authored by Theodore Ts'o's avatar Theodore Ts'o Committed by Greg Kroah-Hartman
Browse files

ext4: always check block group bounds in ext4_init_block_bitmap() 

commit 819b23f1c501b17b9694325471789e6b5cc2d0d2 upstream.

Regardless of whether the flex_bg feature is set, we should always
check to make sure the bits we are setting in the block bitmap are
within the block group bounds.

https://bugzilla.kernel.org/show_bug.cgi?id=199865



Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ac93c718

fs/ext4/balloc.c

+3 −7
Original line number Original line Diff line number Diff line
@@ -184,7 +184,6 @@ static int ext4_init_block_bitmap(struct super_block *sb, 
	unsigned int bit, bit_max;

	unsigned int bit, bit_max;

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	ext4_fsblk_t start, tmp;

	ext4_fsblk_t start, tmp;

	int flex_bg = 0;

	struct ext4_group_info *grp;

	struct ext4_group_info *grp;





	J_ASSERT_BH(bh, buffer_locked(bh));

	J_ASSERT_BH(bh, buffer_locked(bh));
@@ -217,22 +216,19 @@ static int ext4_init_block_bitmap(struct super_block *sb, 




	start = ext4_group_first_block_no(sb, block_group);

	start = ext4_group_first_block_no(sb, block_group);





	if (ext4_has_feature_flex_bg(sb))

		flex_bg = 1;



	/* Set bits for block and inode bitmaps, and inode table */

	/* Set bits for block and inode bitmaps, and inode table */

	tmp = ext4_block_bitmap(sb, gdp);

	tmp = ext4_block_bitmap(sb, gdp);

	if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))

	if (ext4_block_in_group(sb, tmp, block_group))

		ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);

		ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);





	tmp = ext4_inode_bitmap(sb, gdp);

	tmp = ext4_inode_bitmap(sb, gdp);

	if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))

	if (ext4_block_in_group(sb, tmp, block_group))

		ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);

		ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);





	tmp = ext4_inode_table(sb, gdp);

	tmp = ext4_inode_table(sb, gdp);

	for (; tmp < ext4_inode_table(sb, gdp) +

	for (; tmp < ext4_inode_table(sb, gdp) +

		     sbi->s_itb_per_group; tmp++) {

		     sbi->s_itb_per_group; tmp++) {

		if (!flex_bg || ext4_block_in_group(sb, tmp, block_group))

		if (ext4_block_in_group(sb, tmp, block_group))

			ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);

			ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);

	}

	}