---
cve: "CVE-2026-90046"
severity: "HIGH"
cvss: 7.8
epss: "18.4%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-09-16 11:17:17"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-18T05:41:27+02:00"
---

# CVE-2026-90046

> 7.8 HIGH

## Beschreibung

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

mm/page_alloc: don't spin_trylock() in NMI on UP

Patch series "mm/page_alloc: fixes for free_pages_nolock() on RT/UP".

Pre-existing bugs found by Sashiko during review of this other series:
https://lore.kernel.org/all/20260703-alloc-trylock-v5-0-c87b714e19d3@google.com/

I have not reproduced these bugs, and I suspect there is no real-world
user that is affected by them.


This patch (of 2):

As noted in can_spin_trylock(), using this is unsafe in this context. 
commit 620b46ed6ae17 ("mm/page_alloc: return NULL early from
alloc_frozen_pages_nolock() in NMI on UP") fixed this on the alloc side
but missed the free side.

Impact: If BPF programs using these features in NMI (probably tracing) are
present on non-SMP builds this might crash the kernel and is probably
exploitable by local attackers for privilege escalation.

## 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/06c76d3c389ff504052f64b1acee44651bd847fa>
- <https://git.kernel.org/stable/c/68a069b407303e71db371df85036101e8ff59280>
- <https://git.kernel.org/stable/c/3105ae628fb785d48b49256468be4f21a7b3cfc0>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-90046) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_