reiserfs: check directory items on read from disk
[ Upstream commit
13d257503c0930010ef9eed78b689cec417ab741 ]
While verifying the leaf item that we read from the disk, reiserfs
doesn't check the directory items, this could cause a crash when we
read a directory item from the disk that has an invalid deh_location.
This patch adds a check to the directory items read from the disk that
does a bounds check on deh_location for the directory entries. Any
directory entry header with a directory entry offset greater than the
item length is considered invalid.
Link: https://lore.kernel.org/r/20210709152929.766363-1-chouhan.shreyansh630@gmail.com
Reported-by: syzbot+c31a48e6702ccb3d64c9@syzkaller.appspotmail.com
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>