Improper control of a resource through its lifetime in Linux kernel - CVE-2026-64059

Detailed vulnerability description

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper state management in netfs_perform_write() when handling folio private data during buffered writes. A local user can trigger repeated writes that cause multiple private-data attachments and reference leaks to cause a denial of service.

The issue can leak folio references, netfs_folio structures, or netfs_group references under certain write-handling conditions.

How to mitigate CVE-2026-64059

Sources

• https://git.kernel.org/stable/c/0969ea8370bad0e4fb6131b6a7bed9e7ec522ac7
• https://git.kernel.org/stable/c/551b5c71ee312ca7646ddb605231c1016e8cbb18
• https://git.kernel.org/stable/c/7f040243c74d72b45b22246c7d9e621fbeab44ac
• https://git.kernel.org/stable/c/ccde2ac757c713535b224233a296de40efe5212d