CVE-2025-40067

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> fs/ntfs3: reject index allocation if $BITMAP is empty but blocks exist<br /> <br /> Index allocation requires at least one bit in the $BITMAP attribute to<br /> track usage of index entries. If the bitmap is empty while index blocks<br /> are already present, this reflects on-disk corruption.<br /> <br /> syzbot triggered this condition using a malformed NTFS image. During a<br /> rename() operation involving a long filename (which spans multiple<br /> index entries), the empty bitmap allowed the name to be added without<br /> valid tracking. Subsequent deletion of the original entry failed with<br /> -ENOENT, due to unexpected index state.<br /> <br /> Reject such cases by verifying that the bitmap is not empty when index<br /> blocks exist.