Description
Pages belonging to largepage shared memory objects were not explicitly wired. When sendfile(2) transmitted such an object with the SF_NOCACHE flag, it freed the underlying pages after transmission even though existing mappings still referred to them.
An unprivileged local user can abuse the bug to access freed kernel memory. This can be exploited to escalate privileges.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| FreeBSD | FreeBSD | 15.1-RELEASE – < p1, 15.0-RELEASE – < p11, 14.4-RELEASE – < p7, 14.3-RELEASE – < p16 | p1 |
Advisories 1
- WID-SEC-2026-2165 FreeBSD Project FreeBSD OS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 19, 2026