Executive brief
OCFS2 is a clustered filesystem used in enterprise storage systems. A validation weakness allowed malformed inode metadata to be accepted, potentially leading to privilege escalation or denial of service when processing crafted filesystem images.
Technical details
The vulnerability exists in the OCFS2 dinode validation logic, specifically in ocfs2_validate_inode_block(). The validator accepted any non-zero i_mode value without checking that the type bits corresponded to one of the seven canonical POSIX file types. Malformed dinodes with unrecognized i_mode type bits would be copied verbatim into the in-core inode, bypassing downstream type dispatch. The fix adds structural validation using fs_umode_to_ftype() to reject dinodes whose type bits are non-canonical, preventing malformed metadata from reaching ocfs2_populate_inode().
Affected products
- Linux Linux kernel <UNKNOWN>
Timeline
- 2026-08-15: disclosed