---
id: CVE-2026-93216
title: >-
  In the Linux kernel, the following vulnerability has been resolved:


  mm/page_owner: use memcg_data snapshot to avoid TOCTOU in
  print_page_owner_memcg()


  print_page_owner_memcg() reads page->memcg_data via READ_ONCE() at the

  start to guar…
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  mm/page_owner: use memcg_data snapshot to avoid TOCTOU in
  print_page_owner_memcg()


  print_page_owner_memcg() reads page->memcg_data via READ_ONCE() at the

  start to guar…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= fcf8935832b86d3437f00e732c6d0d4d2819d6a9 <
    46761406e14381dc35f498c247a87565b87ea2ef
  - >-
    Linux >= fcf8935832b86d3437f00e732c6d0d4d2819d6a9 <
    90f095b816e25c6a9e4446d299bac5007fdcb3df
  - Linux 5.18
published: '2026-09-24'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T16:17:16.670'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93216'
references:
  - url: 'https://git.kernel.org/stable/c/46761406e14381dc35f498c247a87565b87ea2ef'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/90f095b816e25c6a9e4446d299bac5007fdcb3df'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-24T15:45:56.670Z'
---

## Overview

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

mm/page_owner: use memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()

print_page_owner_memcg() reads page->memcg_data via READ_ONCE() at the
start to guard against tail pages and NULL data.  However, it later
re-reads page->memcg_data locklessly in two places:

1: page_memcg_check(page)

2: PageMemcgKmem(page) (via folio_memcg_kmem(), which includes
   VM_BUG_ON assertions for tail pages and MEMCG_DATA_OBJEXTS)

If the page is concurrently freed and reallocated as a THP tail page or
slab page between these calls, the VM_BUG_ON assertions can trigger on
CONFIG_DEBUG_VM=y builds, crashing the kernel.

Fix both TOCTOU issues by using the memcg_data snapshot throughout.

## Remediation

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