---
id: CVE-2026-89919
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  KVM: s390: keyop: use mmu_lock to read gmap->asce

  Every other dat_* consumer in this file (kvm_s390_get_skeys,
  set_skeys, get_cmma_bits, set_cmma_bits, MEM_CLR_CMMA,
  k…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  KVM: s390: keyop: use mmu_lock to read gmap->asce

  Every other dat_* consumer in this file (kvm_s390_get_skeys,
  set_skeys, get_cmma_bits, set_cmma_bits, MEM_CLR_CMMA,
  k…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0ee4ddc1647b8b3b9e7a94d798a1774a764428c1 <
    ae452b990e0544425f77045351c56e77158858e7
  - >-
    Linux >= 0ee4ddc1647b8b3b9e7a94d798a1774a764428c1 <
    da07a751efa4583385f9f0f47113549fe8871242
  - Linux 7.0
published: '2026-09-16'
updated: '2026-09-16'
sourceUpdated: '2026-09-16T15:18:18.130'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89919'
references:
  - url: 'https://git.kernel.org/stable/c/ae452b990e0544425f77045351c56e77158858e7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/da07a751efa4583385f9f0f47113549fe8871242'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-16T10:53:53.973Z'
epss: 0.00154
epssPercentile: 0.04907
---

## Overview

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

KVM: s390: keyop: use mmu_lock to read gmap->asce

Every other dat_* consumer in this file (kvm_s390_get_skeys,
set_skeys, get_cmma_bits, set_cmma_bits, MEM_CLR_CMMA,
kvm_s390_fixup_prefix, kvm_test_age_gfn, kvm_age_gfn) reads
kvm->arch.gmap->asce *inside* the mmu_lock read-side. keyop is the only
outlier.

gmap->asce is mutated under write_lock(mmu_lock) by gmap_set_limit()
and keyop might use a stale asce value for walking as KVM_S390_KEYOP
and KVM_S390_VM_MEM_LIMIT_SIZE can run concurrently. This can result
in memory corruption.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.