---
id: CVE-2026-89459
title: 's390/percpu: Fix MVIY_PERCPU() with older binutils'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  s390/percpu: Fix MVIY_PERCPU() with older binutils

  Commit a737737cdb9c ("s390/percpu: Infrastructure for more efficient
  this_cpu operations") introduced MVIY_PERCPU(),…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-88
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= a737737cdb9c94e40a9926cdc2320f874c05d709 <
    91770b08a120967077ae78600612f18bc5ee3caf
  - >-
    Linux >= a737737cdb9c94e40a9926cdc2320f874c05d709 <
    101782f8945a125044347312d74d488c05741c4a
  - Linux 7.2
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:47:08.639Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89459'
references:
  - url: 'https://git.kernel.org/stable/c/91770b08a120967077ae78600612f18bc5ee3caf'
  - url: 'https://git.kernel.org/stable/c/101782f8945a125044347312d74d488c05741c4a'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89459.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-89459'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532530'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89459'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89459'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89459.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00141
epssPercentile: 0.03433
scores:
  cna: 7
  vendor: 5.5
ingestedAt: '2026-09-14T15:23:07.475Z'
---

## Overview

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

s390/percpu: Fix MVIY_PERCPU() with older binutils

Commit a737737cdb9c ("s390/percpu: Infrastructure for more efficient
this_cpu operations") introduced MVIY_PERCPU(), which stringifies
arguments that are already C string literals. This generates an
assembler macro invocation with whitespace-separated quoted arguments:

  GEN_MVIY "459712" "%r3"

GNU as versions prior to binutils 2.39 drop the separating whitespace
between quoted macro arguments during input scrubbing. They
consequently parse the invocation as a single argument and emit
repeated warnings:

  Warning: missing closing `"'

The .ifc in GEN_MVIY never matches and GNU as exits successfully
without emitting the mviy instruction. As a result, the interrupted
per-CPU sequence is not marked in lowcore and the exception return
path cannot repair the per-CPU address register after migration.

All MVIY_PERCPU() callers pass C string literals. Use them directly
and separate the assembler macro arguments with an explicit comma. The
resulting invocation is:

  GEN_MVIY 459712, %r3

This form is unambiguous for GNU as and LLVM's integrated assembler.
This behavior was fixed in GNU as from binutils 2.39, but Linux
supports binutils 2.30.

## Affected

- `Linux >= a737737cdb9c94e40a9926cdc2320f874c05d709 < 91770b08a120967077ae78600612f18bc5ee3caf`
- `Linux >= a737737cdb9c94e40a9926cdc2320f874c05d709 < 101782f8945a125044347312d74d488c05741c4a`
- `Linux 7.2`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89459.json)