---
id: CVE-2025-22013
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state

  There are several problems with the way hyp code lazily saves the host's
  FPSIMD/SVE state, including:
  …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state

  There are several problems with the way hyp code lazily saves the host's
  FPSIMD/SVE state, including:
  …
severity: high
cvss: 7.3
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H'
cwe:
  - CWE-99
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 6.2, < 6.6.85'
  - 'linux_kernel >= 6.7, < 6.12.21'
  - 'linux_kernel >= 6.13, < 6.13.9'
  - linux_kernel = 6.14
patched:
  - linux_kernel 6.13.9
published: '2025-04-08'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:18:13.067'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-22013'
references:
  - url: 'https://git.kernel.org/stable/c/04c50cc23a492c4d43fdaefc7c1ecc0ff6f7b82e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5289ac43b69c61a49c75720921f2008005a31c43'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/79e140bba70bcacc5fe15bf8c0b958793fd7d56f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/806d5c1e1d2e5502175a24bf70f251648d99c36a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/900b444be493b7f404898c785d6605b177a093d0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fbc7e61195e23f744814e78524b73b59faa54ab4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-22013.json
  - url: 'https://access.redhat.com/security/cve/CVE-2025-22013'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2358222'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2025-22013'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-22013'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2025040843-CVE-2025-22013-c885@gregkh/T
  - url: 'https://access.redhat.com/errata/RHSA-2025:3510'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00212
epssPercentile: 0.11394
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-15T21:44:00.434508Z'
scores:
  nvd: 7.3
  vendor: 5.5
  cna: 7.3
ingestedAt: '2026-10-15T22:48:25.471Z'
---

## Overview

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

KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state

There are several problems with the way hyp code lazily saves the host's
FPSIMD/SVE state, including:

* Host SVE being discarded unexpectedly due to inconsistent
  configuration of TIF_SVE and CPACR_ELx.ZEN. This has been seen to
  result in QEMU crashes where SVE is used by memmove(), as reported by
  Eric Auger:

  https://issues.redhat.com/browse/RHEL-68997

* Host SVE state is discarded *after* modification by ptrace, which was an
  unintentional ptrace ABI change introduced with lazy discarding of SVE state.

* The host FPMR value can be discarded when running a non-protected VM,
  where FPMR support is not exposed to a VM, and that VM uses
  FPSIMD/SVE. In these cases the hyp code does not save the host's FPMR
  before unbinding the host's FPSIMD/SVE/SME state, leaving a stale
  value in memory.

Avoid these by eagerly saving and "flushing" the host's FPSIMD/SVE/SME
state when loading a vCPU such that KVM does not need to save any of the
host's FPSIMD/SVE/SME state. For clarity, fpsimd_kvm_prepare() is
removed and the necessary call to fpsimd_save_and_flush_cpu_state() is
placed in kvm_arch_vcpu_load_fp(). As 'fpsimd_state' and 'fpmr_ptr'
should not be used, they are set to NULL; all uses of these will be
removed in subsequent patches.

Historical problems go back at least as far as v5.17, e.g. erroneous
assumptions about TIF_SVE being clear in commit:

  8383741ab2e773a9 ("KVM: arm64: Get rid of host SVE tracking/saving")

... and so this eager save+flush probably needs to be backported to ALL
stable trees.

## Affected

- `linux_kernel >= 6.2, < 6.6.85`
- `linux_kernel >= 6.7, < 6.12.21`
- `linux_kernel >= 6.13, < 6.13.9`
- `linux_kernel = 6.14`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.13.9`

## Vendor advisories

- **RHSA-2025:3510** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.4), Red Hat Enterprise Linux BaseOS EUS (v.9.4), Red Hat CodeReady Linux Builder EUS (v.9.4), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4), Red Hat Enterprise Linux Real Time EUS (v.9.4) · released 2025-04-02 · [advisory](https://access.redhat.com/errata/RHSA-2025:3510)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-22013.json)