Re: [PATCH] ext4: Fix ext4_empty_dir() for directories with holes

On Wed, Nov 27, 2019 at 02:12:58PM +0100, Jan Kara wrote:

Function ext4_empty_dir() doesn't correctly handle directories with holes and crashes on bh->b_data dereference when bh is NULL. Reorganize the loop to use 'offset' variable all the times instead of comparing pointers to current direntry with bh->b_data pointer. Also add more strict checking of '.' and '..' directory entries to avoid entering loop in possibly invalid state on corrupted filesystems.

References: CVE-2019-19037 CC: stable@vger.kernel.org Fixes: 4e19d6b65fb4 ("ext4: allow directory holes") Signed-off-by: Jan Kara jack@suse.cz

Thanks, applied.

- Ted