CVE-2024-42304

The syzbot constructs a directory that has no dirblock but is non-inline, i.e. the first directory block is a hole. And no errors are reported when creating files in this directory. Then, we get a directory block without '.' and '..' but with a valid dentry. This may cause some code that relies on dot or dotdot (such as make_indexed_dir()) to crash.

This vulnerability is rated as Moderate severity for Red Hat Enterprise Linux because exploitation requires local access to mount a specially corrupted storage image or manipulate filesystem structures, limiting the blast radius to a local denial of service. Standard Red Hat deployments do not permit unprivileged users to mount arbitrary storage devices or filesystem images, restricting exposure under typical configurations. Environments where untrusted users possess privileges to mount crafted ext4 volumes could experience a kernel crash when creating directory entries on affected filesystems.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.