---
cve: "CVE-2026-89841"
severity: "HIGH"
cvss: 7.8
epss: "0.2%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-16 11:16:50"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T06:06:46+02:00"
---

# CVE-2026-89841

> 7.8 HIGH

## Beschreibung

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

f2fs: only redirty pinned folios in redirty_blocks

redirty_blocks() pins folios with read_cache_folio() and then walks the
same range again with filemap_lock_folio() to redirty them and drop the
references it took.

Commit 5951fee46bef ("f2fs: Use a folio in redirty_blocks()") changed
the second pass to a do/while loop. If read_cache_folio() fails before
anything is pinned, page_idx does not advance but the cleanup loop still
runs once.

If readahead has already populated the failed folio in page cache, that
extra iteration finds it and folio_put_refs(folio, 2) drops one
reference too many. Later drop_caches or reclaim can then report
"BUG: Bad page state".

Only redirty the range that was pinned successfully.

## CVSS-Vektor

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

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

## Patch verfügbar (OSV)

- Kernel ≥ 6.18.51
- Kernel ≥ 7.2.5

## Referenzen

- <https://git.kernel.org/stable/c/445e4a1e6025ecd5312e9a95c1b234192c976ca1>
- <https://git.kernel.org/stable/c/89c65ec3c18903de763cf567c96ab3ef60e5f3b0>
- <https://git.kernel.org/stable/c/85171332742e741ccd6f401c69b6e0d698119e72>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-89841) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_