---
id: CVE-2026-89457
title: 's390/dasd: Guard sysfs discipline callbacks against unallocated private data'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  s390/dasd: Guard sysfs discipline callbacks against unallocated private data

  Several sysfs show/store handlers call a discipline callback that
  dereferences device->pri…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-476
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 <
    644b666c202cce12ccfcf9ded67089b18f4f7659
  - >-
    Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 <
    4a042d8e5f34282577ece50515cea8bb1246914d
  - >-
    Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 <
    bd8b4572528f9604a13bf3c7c2a167f5cf222f72
  - >-
    Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 <
    57db27ccc162afe0726cffec0ae62e410ed2d0e9
  - >-
    Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 <
    536407b272402af679155910d7fdeeb4834eefb9
  - >-
    Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 <
    6452c13646af7c13d7f6668b6690cfb2427e7f7b
  - >-
    Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 <
    449f3bada7a9fad8b8cdf4bb20baf27ee9ca56c5
  - >-
    Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 <
    2a1780f9fc2493bd34c418a0be6fc58943afcecf
  - Linux 5.3
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:47:06.711Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89457'
references:
  - url: 'https://git.kernel.org/stable/c/644b666c202cce12ccfcf9ded67089b18f4f7659'
  - url: 'https://git.kernel.org/stable/c/4a042d8e5f34282577ece50515cea8bb1246914d'
  - url: 'https://git.kernel.org/stable/c/bd8b4572528f9604a13bf3c7c2a167f5cf222f72'
  - url: 'https://git.kernel.org/stable/c/57db27ccc162afe0726cffec0ae62e410ed2d0e9'
  - url: 'https://git.kernel.org/stable/c/536407b272402af679155910d7fdeeb4834eefb9'
  - url: 'https://git.kernel.org/stable/c/6452c13646af7c13d7f6668b6690cfb2427e7f7b'
  - url: 'https://git.kernel.org/stable/c/449f3bada7a9fad8b8cdf4bb20baf27ee9ca56c5'
  - url: 'https://git.kernel.org/stable/c/2a1780f9fc2493bd34c418a0be6fc58943afcecf'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89457.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89457'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532055'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89457'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89457'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89457.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00177
epssPercentile: 0.07155
ingestedAt: '2026-09-14T15:23:07.453Z'
---

## Overview

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

s390/dasd: Guard sysfs discipline callbacks against unallocated private data

Several sysfs show/store handlers call a discipline callback that
dereferences device->private, either directly or through the
DASD_DEFINE_ATTR() macro. During dasd_generic_set_online() the discipline
is assigned before check_device() allocates device->private, so an
unprivileged read of one of these world-readable attributes in that window
dereferences a NULL pointer and panics.

Guard the dereference inside each callback that actually touches
device->private.

## Affected

- `Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 < 644b666c202cce12ccfcf9ded67089b18f4f7659`
- `Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 < 4a042d8e5f34282577ece50515cea8bb1246914d`
- `Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 < bd8b4572528f9604a13bf3c7c2a167f5cf222f72`
- `Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 < 57db27ccc162afe0726cffec0ae62e410ed2d0e9`
- `Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 < 536407b272402af679155910d7fdeeb4834eefb9`
- `Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 < 6452c13646af7c13d7f6668b6690cfb2427e7f7b`
- `Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 < 449f3bada7a9fad8b8cdf4bb20baf27ee9ca56c5`
- `Linux >= c729696bcf8b23450043dd9c9972c15e53419ae4 < 2a1780f9fc2493bd34c418a0be6fc58943afcecf`
- `Linux 5.3`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89457.json)