CVE-2026-64600

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A race condition exists in the XFS filesystem copy-on-write implementation. The functions xfs reflink fill cow hole() and xfs reflink fill delalloc() cycle the ILOCK to acquire a transaction, causing the data fork and cow fork mappings to become stale. While the cow fork mapping is refreshed, the data fork mapping is not. Consequently, xfs bmap trim cow() may query the refcount btree using incorrect physical blocks, leading to an inaccurate shared value. If shared is false, a directio write may proceed using the stale data fork mapping, potentially allowing local privilege escalation.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.