---
id: CVE-2026-93217
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/madvise: skip device-private PMDs in cold and pageout walks

  madvise_cold_or_pageout_pte_range() takes pmd_trans_huge_lock(), whose
  pmd_is_huge() check returns true …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/madvise: skip device-private PMDs in cold and pageout walks

  madvise_cold_or_pageout_pte_range() takes pmd_trans_huge_lock(), whose
  pmd_is_huge() check returns true …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 368076f52ebeecd33e10a9f80905d7508b6b6149 <
    5c0d7b658cda62cd17cb3652783386d5608030ef
  - >-
    Linux >= 368076f52ebeecd33e10a9f80905d7508b6b6149 <
    d4b76d0b03cb49611312ecc4bcfb55ccdf0843e2
  - Linux 6.19
published: '2026-09-24'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T16:17:16.790'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93217'
references:
  - url: 'https://git.kernel.org/stable/c/5c0d7b658cda62cd17cb3652783386d5608030ef'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d4b76d0b03cb49611312ecc4bcfb55ccdf0843e2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-24T15:45:56.669Z'
epss: 0.00155
epssPercentile: 0.0394
---

## Overview

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

mm/madvise: skip device-private PMDs in cold and pageout walks

madvise_cold_or_pageout_pte_range() takes pmd_trans_huge_lock(), whose
pmd_is_huge() check returns true for a device-private PMD.  The subsequent
!pmd_present() branch has a VM_BUG_ON() asserting migration is the only
allowed non-present case; a device-private PMD trips it.

Skip device-private PMDs in that non-present branch and continue to
huge_unlock before calling pmd_folio().  Downgrade the check to
VM_WARN_ON_ONCE() so an unexpected PMD softleaf logs a warning rather than
panicking.  Drop the thp_migration_supported() guard: it expands to
IS_ENABLED(CONFIG_ARCH_SUPPORTS_PMD_SOFTLEAF), and both
pmd_is_migration_entry() and pmd_is_device_private_entry() already return
false when that config is not selected, so the guard suppresses only the
case where the warning would already be silent.

Potential trigger: an HMM-based GPU driver races with
madvise(MADV_COLD)/MADV_PAGEOUT: pmd_trans_huge(*pmd) reads true, then
migrate_vma_pages() flips the PMD to a device-private entry before the PMD
lock is acquired.

## Remediation

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