ext4: fix check for block being out of directory size

The check in __ext4_read_dirblock() for block being outside of directory
size was wrong because it compared block number against directory size
in bytes. Fix it.

Fixes: 65f8ea4cd5 ("ext4: check if directory block is within i_size")
CVE: CVE-2022-1184
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Link: https://lore.kernel.org/r/20220822114832.1482-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Jan Kara 2022-08-22 13:48:32 +02:00 committed by Theodore Ts'o
parent 5bdf402a05
commit 61a1d87a32

View File

@ -126,7 +126,7 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode,
struct ext4_dir_entry *dirent;
int is_dx_block = 0;
if (block >= inode->i_size) {
if (block >= inode->i_size >> inode->i_blkbits) {
ext4_error_inode(inode, func, line, block,
"Attempting to read directory block (%u) that is past i_size (%llu)",
block, inode->i_size);