---
id: CVE-2025-68231
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/mempool: fix poisoning order>0 pages with HIGHMEM

  The kernel test has reported:

    BUG: unable to handle page fault for address: fffba000
    #PF: supervisor write ac…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/mempool: fix poisoning order>0 pages with HIGHMEM

  The kernel test has reported:

    BUG: unable to handle page fault for address: fffba000
    #PF: supervisor write ac…
severity: none
published: '2025-12-16'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-68231'
references:
  - url: 'https://git.kernel.org/stable/c/19de79aaea33ee1ea058c8711b3b2b4a7e4decd4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6a13b56537e7b0d97f4bb74e8038ce471f9770d7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a79e49e1704367b635edad1479db23d7cf1fb71a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ea4131665107e66ece90e66bcec1a2f1246cbd41'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ec33b59542d96830e3c89845ff833cf7b25ef172'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00186
epssPercentile: 0.07599
ingestedAt: '2026-10-14T13:30:58.461Z'
---

## Overview

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

mm/mempool: fix poisoning order>0 pages with HIGHMEM

The kernel test has reported:

  BUG: unable to handle page fault for address: fffba000
  #PF: supervisor write access in kernel mode
  #PF: error_code(0x0002) - not-present page
  *pde = 03171067 *pte = 00000000
  Oops: Oops: 0002 [#1]
  CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G                T   6.18.0-rc2-00031-gec7f31b2a2d3 #1 NONE  a1d066dfe789f54bc7645c7989957d2bdee593ca
  Tainted: [T]=RANDSTRUCT
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
  EIP: memset (arch/x86/include/asm/string_32.h:168 arch/x86/lib/memcpy_32.c:17)
  Code: a5 8b 4d f4 83 e1 03 74 02 f3 a4 83 c4 04 5e 5f 5d 2e e9 73 41 01 00 90 90 90 3e 8d 74 26 00 55 89 e5 57 56 89 c6 89 d0 89 f7 <f3> aa 89 f0 5e 5f 5d 2e e9 53 41 01 00 cc cc cc 55 89 e5 53 57 56
  EAX: 0000006b EBX: 00000015 ECX: 001fefff EDX: 0000006b
  ESI: fffb9000 EDI: fffba000 EBP: c611fbf0 ESP: c611fbe8
  DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068 EFLAGS: 00010287
  CR0: 80050033 CR2: fffba000 CR3: 0316e000 CR4: 00040690
  Call Trace:
   poison_element (mm/mempool.c:83 mm/mempool.c:102)
   mempool_init_node (mm/mempool.c:142 mm/mempool.c:226)
   mempool_init_noprof (mm/mempool.c:250 (discriminator 1))
   ? mempool_alloc_pages (mm/mempool.c:640)
   bio_integrity_initfn (block/bio-integrity.c:483 (discriminator 8))
   ? mempool_alloc_pages (mm/mempool.c:640)
   do_one_initcall (init/main.c:1283)

Christoph found out this is due to the poisoning code not dealing
properly with CONFIG_HIGHMEM because only the first page is mapped but
then the whole potentially high-order page is accessed.

We could give up on HIGHMEM here, but it's straightforward to fix this
with a loop that's mapping, poisoning or checking and unmapping
individual pages.

## Remediation

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