---
cve: "CVE-2026-23134"
severity: "LOW"
cvss: 3.1
epss: "11%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-02-14 16:15:53"
tags: [cve, security, low]
source: tsecurity.de CVE-Dossier
exported: "2026-09-06T11:54:43+02:00"
---

# CVE-2026-23134

> 3.1 LOW

## Beschreibung

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

slab: fix kmalloc_nolock() context check for PREEMPT_RT

On PREEMPT_RT kernels, local_lock becomes a sleeping lock. The current
check in kmalloc_nolock() only verifies we're not in NMI or hard IRQ
context, but misses the case where preemption is disabled.

When a BPF program runs from a tracepoint with preemption disabled
(preempt_count > 0), kmalloc_nolock() proceeds to call
local_lock_irqsave() which attempts to acquire a sleeping lock,
triggering:

  BUG: sleeping function called from invalid context
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 6128
  preempt_count: 2, expected: 0

Fix this by checking !preemptible() on PREEMPT_RT, which directly
expresses the constraint that we cannot take a sleeping lock when
preemption is disabled. This encompasses the previous checks for NMI
and hard IRQ contexts while also catching cases where preemption is
disabled.

## Patch verfügbar (OSV)

- Kernel ≥ 6.18.8

## Referenzen

- <https://git.kernel.org/stable/c/f60ba4a97ae3f94e4818722ed2e4d260bbb17b44>
- <https://git.kernel.org/stable/c/99a3e3a1cfc93b8fe318c0a3a5cfb01f1d4ad53c>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-23134) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_