---
id: CVE-2026-98390
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  x86/amd_node: Avoid divide by zero on virtualized systems

  On a virtualized system, the number of nodes does not have a relationship to
  the number of roots
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  x86/amd_node: Avoid divide by zero on virtualized systems

  On a virtualized system, the number of nodes does not have a relationship to
  the number of roots.  A Xen PVH …
severity: medium
published: '2026-10-14'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T14:17:49.873'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98390'
references:
  - url: 'https://git.kernel.org/stable/c/72bd92bd8190d7869ecb462649ca40f297822a33'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9273a90465d58b82aca4bea71451ef6bee084928'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/94e984d8858a3228952b02f84e66610961098cc2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98390.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-98390'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2552195'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-98390'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-98390'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98390.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ingestedAt: '2026-10-14T15:36:13.976Z'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0a4b61d9c2e496b5f0a10e29e355a1465c8738bb <
    9273a90465d58b82aca4bea71451ef6bee084928
  - >-
    Linux >= 0a4b61d9c2e496b5f0a10e29e355a1465c8738bb <
    94e984d8858a3228952b02f84e66610961098cc2
  - >-
    Linux >= 0a4b61d9c2e496b5f0a10e29e355a1465c8738bb <
    72bd92bd8190d7869ecb462649ca40f297822a33
  - Linux c4ad899a33198ab6335732c769835d035e66894a
  - Linux >= 6.17.8 < 6.18
  - Linux 6.18
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-369
epss: 0.00203
epssPercentile: 0.10201
---

## Overview

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

x86/amd_node: Avoid divide by zero on virtualized systems

On a virtualized system, the number of nodes does not have a relationship to
the number of roots.  A Xen PVH dom0 can calculate roots_per_node as 0, which
crashes with a divide by zero in:

  if (count++ % roots_per_node)

because the underlying topology code on Xen ends up making num_nodes
2 and num_roots 1 and the integer division result is 0.

The issue is seen with Xen, but it could affect other systems.

Set roots_per_node to 1 in this case. Print a firmware bug when this is
performed for non-virtualized systems.

  [ bp: Massage commit message. ]

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98390.json)