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Fencer Vulns
high 7.3

CVE-2025-22013 json

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

published 2025-04-08 19 mo ago modified 2026-10-15 24 d ago also EUVD-2025-10342

cvss
7.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

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:

* 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.

Patch / fix

  • Linux Linux 6.6.85, 6.12.21, 6.13.9, 6.14
  • linux Debian 14, Debian 13 6.12.21-1

debian advisories DEBIAN-CVE-2025-22013

  • linux Ubuntu 24.04 LTS 6.8.0-84.84
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1039.41
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1040.42
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1036.40
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1037.37
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1038.44
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1023.25
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1039.43

ubuntu advisories UBUNTU-CVE-2025-22013

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9.4 EUS 5.14.0-427.62.1.el9_4
  • rv RHEL 9.4 EUS 5.14.0-427.62.1.el9_4
  • perf RHEL 9.4 EUS 5.14.0-427.62.1.el9_4
  • rtla RHEL 9.4 EUS 5.14.0-427.62.1.el9_4
  • bpftool RHEL 9.4 EUS 7.3.0-427.62.1.el9_4
  • libperf RHEL 9.4 EUS 5.14.0-427.62.1.el9_4
  • kernel-rt RHEL 9.4 EUS 5.14.0-427.62.1.el9_4
  • kernel-64k RHEL 9.4 EUS 5.14.0-427.62.1.el9_4

red hat advisories RHSA-2025:3510

  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.3.1
  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.39.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.39.1
  • kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.39.1
  • kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.39.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.3.1

suse advisories SUSE-SU-2025:01967-1SUSE-SU-2025:01964-1SUSE-SU-2025:01951-1SUSE-SU-2025:01919-1SUSE-SU-2025:01707-1SUSE-SU-2025:01614-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-22013 updated cvss 5.5

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

  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available “Fix deferred”
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.62.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.62.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.62.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.62.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.62.1.el9_4 Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.62.1.el9_4, perf 5.14.0-427.62.1.el9_4, rtla 5.14.0-427.62.1.el9_4, kernel-devel-matched 5.14.0-427.62.1.el9_4, kernel-64k-devel-matched 5.14.0-427.62.1.el9_4, kernel-debug-devel-matched 5.14.0-427.62.1.el9_4, +6 more Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.62.1.el9_4, kernel 5.14.0-427.62.1.el9_4, kernel-64k 5.14.0-427.62.1.el9_4, kernel-core 5.14.0-427.62.1.el9_4, kernel-tools 5.14.0-427.62.1.el9_4, python3-perf 5.14.0-427.62.1.el9_4, +28 more Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.62.1.el9_4, kernel-rt-core 5.14.0-427.62.1.el9_4, kernel-rt-modules 5.14.0-427.62.1.el9_4, kernel-rt-debug-core 5.14.0-427.62.1.el9_4, kernel-rt-modules-core 5.14.0-427.62.1.el9_4, kernel-rt-debug-modules 5.14.0-427.62.1.el9_4, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.62.1.el9_4, kernel-rt-kvm 5.14.0-427.62.1.el9_4, kernel-rt-core 5.14.0-427.62.1.el9_4, kernel-rt-modules 5.14.0-427.62.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.62.1.el9_4, kernel-rt-debug-core 5.14.0-427.62.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:3510
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
24 d ago

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.3 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.