CVE-2026-89459
Received
Received - Intake
s390/percpu MVIY_PERCPU Macro Handling Flaw in Linux Kernel
Vulnerability report for CVE-2026-89459, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-11
Last updated on: 2026-09-11
Assigner: kernel.org
Description
Description
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.
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| gnu | binutils | to 2.39 (inc) |
| gnu | binutils | From 2.30 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
