---
id: CVE-2026-43303
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/page_alloc: clear page->private in free_pages_prepare()

  Several subsystems (slub, shmem, ttm, etc.) use page->private but don't
  clear it before freeing pages
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  mm/page_alloc: clear page->private in free_pages_prepare()

  Several subsystems (slub, shmem, ttm, etc.) use page->private but don't
  clear it before freeing pages.  When…
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-416
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.18.1, < 6.18.16'
  - 'linux_kernel >= 6.19, < 6.19.6'
  - linux_kernel = 5.18
patched:
  - linux_kernel 6.19.6
published: '2026-05-08'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T09:18:04.847'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-43303'
references:
  - url: 'https://git.kernel.org/stable/c/23b82b7a26182ad840ae67d390d7ec9771e8c00f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3edb8ebbf79b9016040e8f3421d723ae3d542b32'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ac1ea219590c09572ed5992dc233bbf7bb70fef9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d757c793853ec5483eb41ec2942c300b8fa720fb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e7790ab165713b79b1617ce659742ceb3a859d05'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f9719e32a67b4b00b3c9b133e8b5ffa72a26b67b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00171
epssPercentile: 0.05714
ingestedAt: '2026-09-08T13:33:23.990Z'
---

## Overview

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

mm/page_alloc: clear page->private in free_pages_prepare()

Several subsystems (slub, shmem, ttm, etc.) use page->private but don't
clear it before freeing pages.  When these pages are later allocated as
high-order pages and split via split_page(), tail pages retain stale
page->private values.

This causes a use-after-free in the swap subsystem.  The swap code uses
page->private to track swap count continuations, assuming freshly
allocated pages have page->private == 0.  When stale values are present,
swap_count_continued() incorrectly assumes the continuation list is valid
and iterates over uninitialized page->lru containing LIST_POISON values,
causing a crash:

  KASAN: maybe wild-memory-access in range [0xdead000000000100-0xdead000000000107]
  RIP: 0010:__do_sys_swapoff+0x1151/0x1860

Fix this by clearing page->private in free_pages_prepare(), ensuring all
freed pages have clean state regardless of previous use.

## Affected

- `linux_kernel >= 5.18.1, < 6.18.16`
- `linux_kernel >= 6.19, < 6.19.6`
- `linux_kernel = 5.18`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.19.6`