---
id: CVE-2026-72172
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/mm_init: fix uninitialized struct pages for ZONE_DEVICE

  If DAX memory is hotplugged into an unoccupied subsection of an early
  section, section_activate() reuses the…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/mm_init: fix uninitialized struct pages for ZONE_DEVICE

  If DAX memory is hotplugged into an unoccupied subsection of an early
  section, section_activate() reuses the…
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'
cwe:
  - CWE-457
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 6
  - enterprise_linux 9
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T19:17:12.963'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-72172'
references:
  - url: 'https://git.kernel.org/stable/c/11f2826e9ee6f24aaa774e3dcd75abbe4b3091b6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/511a60e71aec308b24722cffc1912bf6befb87bf'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b91e27bce37cab9f35de0059278ebe457ca9878b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c5ef574d57e4a701485c13f26822328c91f05413'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/cd681403a87085562499d60325b7b45d3be11217'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/da5234df0941665f3a3f5b80f3dab94046537be0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72172.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-72172'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2516567'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-72172'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-72172'
  - url: 'https://kernelcve.org/list/?q=CVE-2026-72172'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2026081538-CVE-2026-72172-c8f2@gregkh/T
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - cve.org
  - score-dispute
epss: 0.00169
epssPercentile: 0.06193
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T18:43:19.574652Z'
scores:
  nvd: 7.8
  vendor: 5.5
  cna: 7.8
ingestedAt: '2026-10-16T19:46:24.424Z'
---

## Overview

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

mm/mm_init: fix uninitialized struct pages for ZONE_DEVICE

If DAX memory is hotplugged into an unoccupied subsection of an early
section, section_activate() reuses the unoptimized boot memmap.  However,
compound_nr_pages() still assumes that vmemmap optimization is in effect
and initializes only the reduced number of struct pages.  As a result, the
remaining tail struct pages are left uninitialized, which can later lead
to unexpected behavior or crashes.

Fix this by treating early sections as unoptimized when calculating how
many struct pages to initialize.

## 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 6, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-72172.json)