---
cve: "CVE-2026-64216"
severity: "CRITICAL"
cvss: 9.8
epss: "45%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-07-24 16:16:49"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-04T18:36:45+02:00"
---

# CVE-2026-64216

> 9.8 CRITICAL

## Beschreibung

In the Linux kernel, the following vulnerability has been resolved:

netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()

netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it
is wanting to unlock and compares that to rreq->no_unlock_folio so that it
doesn't unlock a folio being read for netfs_perform_write() or
netfs_write_begin().

However, given that netfs_unlock_abandoned_read_pages() is called _after_
NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to
dereference is the one specified by ->no_unlock_folio as ownership
immediately reverts to the caller.

Fix this by storing the folio pointer instead and using that rather than
the index.  Also fix netfs_unlock_read_folio() where the same applies.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 6.12.106
- Kernel ≥ 6.18.34
- Kernel ≥ 7.0.11

## Referenzen

- <https://git.kernel.org/stable/c/6080fa3ecfbb4448a3b47368629534c09b6ec750>
- <https://git.kernel.org/stable/c/3866d015f33aeedf81338dd99154703bef33faef>
- <https://git.kernel.org/stable/c/dbe556972100fabb8e5a1b3d2163831ff07b1e8e>
- <https://git.kernel.org/stable/c/d4ae8dba90b89e7bb4d1045d1cb26afbaf13ee5c>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-64216) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_