diff options
| author | Jan Kara <jack@suse.cz> | 2024-06-24 18:12:56 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-08-03 10:00:34 +0300 |
| commit | f1834feb25770d1c40f88d37d8a01b66be407db9 (patch) | |
| tree | 2d52dd0d26e3526c09affa2d40aa571d07479f9c /fs/ext2 | |
| parent | d3493d6f0dfb1ab5225b62faa77732983f2187a1 (diff) | |
| download | linux-f1834feb25770d1c40f88d37d8a01b66be407db9.tar.xz | |
ext2: Verify bitmap and itable block numbers before using them
commit 322a6aff03937aa1ece33b4e46c298eafaf9ac41 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext2')
| -rw-r--r-- | fs/ext2/balloc.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index 1bfd6ab11038..b8cfab8f98b9 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -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); |