korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-09-21 12:11:49 +08:00
Code Issues Packages Projects Releases Wiki Activity

ext2: Verify bitmap and itable block numbers before using them

Browse Source 
Verify bitmap block numbers and inode table blocks are sane before using
them for checking bits in the block bitmap.

CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Kara 2024-06-24 17:12:56 +02:00
parent 56e69e5975
commit 322a6aff03
1 changed files with 9 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
fs/ext2/balloc.c
View File

@ -77,26 +77,33 @@ static int ext2_valid_block_bitmap(struct super_block *sb,
ext2_grpblk_t next_zero_bit;
ext2_fsblk_t bitmap_blk;
ext2_fsblk_t group_first_block;
ext2_grpblk_t max_bit;
group_first_block = ext2_group_first_block_no(sb, block_group);
max_bit = ext2_group_last_block_no(sb, block_group) - group_first_block;
/* check whether block bitmap block number is set */
bitmap_blk = le32_to_cpu(desc->bg_block_bitmap);
offset = bitmap_blk - group_first_block;
if (!ext2_test_bit(offset, bh->b_data))
if (offset < 0 || offset > max_bit ||
!ext2_test_bit(offset, bh->b_data))
/* bad block bitmap */
goto err_out;
/* check whether the inode bitmap block number is set */
bitmap_blk = le32_to_cpu(desc->bg_inode_bitmap);
offset = bitmap_blk - group_first_block;
if (!ext2_test_bit(offset, bh->b_data))
if (offset < 0 || offset > max_bit ||
!ext2_test_bit(offset, bh->b_data))
/* bad block bitmap */
goto err_out;
/* check whether the inode table block number is set */
bitmap_blk = le32_to_cpu(desc->bg_inode_table);
offset = bitmap_blk - group_first_block;
if (offset < 0 || offset > max_bit ||
offset + EXT2_SB(sb)->s_itb_per_group - 1 > max_bit)
goto err_out;
next_zero_bit = ext2_find_next_zero_bit(bh->b_data,
offset + EXT2_SB(sb)->s_itb_per_group,
offset);