---
id: CVE-2026-89559
title: 'libnvdimm/labels: Prevent integer overflow in __nd_label_validate()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  libnvdimm/labels: Prevent integer overflow in __nd_label_validate()

  The on-media namespace index field nslot is a u32 read from the DIMM
  label storage area.  __nd_labe…
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'
cvssSource: cna
cwe:
  - CWE-787
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 564e871aa66f548a947b23808d3140f326381f0c <
    b4975f2ff6c82adc24ae547f029f82530ba43cfe
  - >-
    Linux >= 564e871aa66f548a947b23808d3140f326381f0c <
    6030597ec683d1e5b46445f888bb5c7776b5a0c4
  - >-
    Linux >= 564e871aa66f548a947b23808d3140f326381f0c <
    1c391696d2791f82ae462e11da9a0d96f90b240c
  - >-
    Linux >= 564e871aa66f548a947b23808d3140f326381f0c <
    93967bfb17dab66642c57e609c99e1a91fe11278
  - >-
    Linux >= 564e871aa66f548a947b23808d3140f326381f0c <
    e057efcc9c71d90099d9ee00bed0748d0e9fd586
  - >-
    Linux >= 564e871aa66f548a947b23808d3140f326381f0c <
    09e649117c54b7e1c004f22eaa19efbadd9ac856
  - >-
    Linux >= 564e871aa66f548a947b23808d3140f326381f0c <
    69a734359639fca16a0dd73ab17a34943e76c68b
  - >-
    Linux >= 564e871aa66f548a947b23808d3140f326381f0c <
    037770686126155eafc44501312989e2837b9659
  - Linux 4.13
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T19:24:09.691777Z'
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:48:52.683Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89559'
references:
  - url: 'https://git.kernel.org/stable/c/b4975f2ff6c82adc24ae547f029f82530ba43cfe'
  - url: 'https://git.kernel.org/stable/c/6030597ec683d1e5b46445f888bb5c7776b5a0c4'
  - url: 'https://git.kernel.org/stable/c/1c391696d2791f82ae462e11da9a0d96f90b240c'
  - url: 'https://git.kernel.org/stable/c/93967bfb17dab66642c57e609c99e1a91fe11278'
  - url: 'https://git.kernel.org/stable/c/e057efcc9c71d90099d9ee00bed0748d0e9fd586'
  - url: 'https://git.kernel.org/stable/c/09e649117c54b7e1c004f22eaa19efbadd9ac856'
  - url: 'https://git.kernel.org/stable/c/69a734359639fca16a0dd73ab17a34943e76c68b'
  - url: 'https://git.kernel.org/stable/c/037770686126155eafc44501312989e2837b9659'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89559.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89559'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532126'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89559'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89559'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89559.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00169
epssPercentile: 0.06197
scores:
  cna: 7.8
  vendor: 7
ingestedAt: '2026-09-14T15:23:07.451Z'
---

## Overview

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

libnvdimm/labels: Prevent integer overflow in __nd_label_validate()

The on-media namespace index field nslot is a u32 read from the DIMM
label storage area.  __nd_label_validate() bounds it against the config
area size, but sizeof_namespace_label() returns unsigned, so the product
nslot * label_size is evaluated in 32-bit and wraps modulo 2^32 before
the comparison.  A crafted nslot passes the bound and is then used as the
loop trip count in nd_label_data_init(), whose memset() walks off the end
of the config_size buffer: an out-of-bounds write.

The field is not trusted -- it comes from the medium, or from userspace
via ND_CMD_SET_CONFIG_DATA.  Evaluate the product in 64-bit so the bound
check is exact; conforming labels are unaffected.

The check was safe when introduced by commit 4a826c83db4e ("libnvdimm:
namespace indices: read and validate"): it multiplied by sizeof(struct
nd_namespace_label), a size_t, so on a 64-bit build the product did not
wrap.  Commit 564e871aa66f ("libnvdimm, label: add v1.2 nvdimm label
definitions") narrowed it to 32 bits when the label size became a runtime
value read via sizeof_namespace_label().

## Affected

- `Linux >= 564e871aa66f548a947b23808d3140f326381f0c < b4975f2ff6c82adc24ae547f029f82530ba43cfe`
- `Linux >= 564e871aa66f548a947b23808d3140f326381f0c < 6030597ec683d1e5b46445f888bb5c7776b5a0c4`
- `Linux >= 564e871aa66f548a947b23808d3140f326381f0c < 1c391696d2791f82ae462e11da9a0d96f90b240c`
- `Linux >= 564e871aa66f548a947b23808d3140f326381f0c < 93967bfb17dab66642c57e609c99e1a91fe11278`
- `Linux >= 564e871aa66f548a947b23808d3140f326381f0c < e057efcc9c71d90099d9ee00bed0748d0e9fd586`
- `Linux >= 564e871aa66f548a947b23808d3140f326381f0c < 09e649117c54b7e1c004f22eaa19efbadd9ac856`
- `Linux >= 564e871aa66f548a947b23808d3140f326381f0c < 69a734359639fca16a0dd73ab17a34943e76c68b`
- `Linux >= 564e871aa66f548a947b23808d3140f326381f0c < 037770686126155eafc44501312989e2837b9659`
- `Linux 4.13`

## 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 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89559.json)