---
cve: "CVE-2026-89748"
severity: "HIGH"
cvss: 7.8
epss: "0.2%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-11 20:20:05"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T00:31:16+02:00"
---

# CVE-2026-89748

> 7.8 HIGH

## Beschreibung

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

tracing: Fix retry exhaustion in simple ring buffer reader swap

simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
post-decrements it only after a failed link replacement. On the final
attempt, a successful replacement leaves retry at zero, while a failed
replacement leaves it at -1.

The current !retry test reverses both outcomes. It returns an error after
a successful final replacement, leaving the link update complete but the
reader bookkeeping unfinished. After a failed final replacement, it
falls through and updates the head and reader pointers as though the
replacement succeeded, which can corrupt the ring.

Treat only a negative counter as exhaustion and return the documented
-EBUSY error.

## 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 ≥ 7.2.4

## Referenzen

- <https://git.kernel.org/stable/c/df02489aa3aa1834659f0d20c89f7d212047d268>
- <https://git.kernel.org/stable/c/e0d3aed7b12cf37b74c7cc5265073d0263b49cde>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-89748) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_