---
id: CVE-2026-98653
title: 'KVM: s390: Fix _gaccess_shadow_fault()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  KVM: s390: Fix _gaccess_shadow_fault()

  In some circumstances, it is possible that the page of nested guest
  memory that is being shadowed is not present at all in the p…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= e38c884df92119d96f652d51f82661dd2fc0b885 <
    94c43c7df46433ed4d1e18f13770b019ba977bd8
  - >-
    Linux >= e38c884df92119d96f652d51f82661dd2fc0b885 <
    faff4c8ff3dbec6d71b89dd281a0d17c4478fa44
  - Linux 7.0
published: '2026-10-18'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T09:23:22.624Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98653'
references:
  - url: 'https://git.kernel.org/stable/c/94c43c7df46433ed4d1e18f13770b019ba977bd8'
  - url: 'https://git.kernel.org/stable/c/faff4c8ff3dbec6d71b89dd281a0d17c4478fa44'
tags:
  - cve.org
ingestedAt: '2026-10-18T15:45:12.226Z'
---

## Overview

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

KVM: s390: Fix _gaccess_shadow_fault()

In some circumstances, it is possible that the page of nested guest
memory that is being shadowed is not present at all in the parent guest
gmap. dat_entry_walk() will not find any leaf entry and return with
-ENOENT, which will erroneously be propagated all the way to userspace.

Fix by manually calling gmap_link() on the memory of the nested guest
that is being shadowed if the mapping was not already present.

## Affected

- `Linux >= e38c884df92119d96f652d51f82661dd2fc0b885 < 94c43c7df46433ed4d1e18f13770b019ba977bd8`
- `Linux >= e38c884df92119d96f652d51f82661dd2fc0b885 < faff4c8ff3dbec6d71b89dd281a0d17c4478fa44`
- `Linux 7.0`

## Remediation

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