---
id: CVE-2022-50230
title: 'arm64: set UXN on swapper page tables'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  arm64: set UXN on swapper page tables

  [ This issue was fixed upstream by accident in c3cee924bd85 ("arm64:
    head: cover entire kernel image in initial ID map") as par…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 18107f8a2df6bf1c6cac8d0713f757f866d5af51 <
    9283e708a9b8529e7aafac9ab5c5c79a9fab8846
  - >-
    Linux >= 18107f8a2df6bf1c6cac8d0713f757f866d5af51 <
    c3cee924bd855184d15bc4aa6088dcf8e2c1394c
  - Linux 5.13
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T20:07:26.420314Z'
published: '2025-06-18'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:10:29.990Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2022-50230'
references:
  - url: 'https://git.kernel.org/stable/c/9283e708a9b8529e7aafac9ab5c5c79a9fab8846'
  - url: 'https://git.kernel.org/stable/c/c3cee924bd855184d15bc4aa6088dcf8e2c1394c'
tags:
  - cve.org
epss: 0.002
epssPercentile: 0.09901
ingestedAt: '2026-11-05T22:38:31.706Z'
---

## Overview

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

arm64: set UXN on swapper page tables

[ This issue was fixed upstream by accident in c3cee924bd85 ("arm64:
  head: cover entire kernel image in initial ID map") as part of a
  large refactoring of the arm64 boot flow. This simple fix is therefore
  preferred for -stable backporting ]

On a system that implements FEAT_EPAN, read/write access to the idmap
is denied because UXN is not set on the swapper PTEs. As a result,
idmap_kpti_install_ng_mappings panics the kernel when accessing
__idmap_kpti_flag. Fix it by setting UXN on these PTEs.

## Affected

- `Linux >= 18107f8a2df6bf1c6cac8d0713f757f866d5af51 < 9283e708a9b8529e7aafac9ab5c5c79a9fab8846`
- `Linux >= 18107f8a2df6bf1c6cac8d0713f757f866d5af51 < c3cee924bd855184d15bc4aa6088dcf8e2c1394c`
- `Linux 5.13`

## Remediation

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