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

Type: advisorySource: Official CVE List1 source record

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: 8383741ab

Announced Source revision 1
Original source ↗

CVE-2025-22013

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2025-22013

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "c4ab60a86c5ed7c0d727c6dc8cec352e16bc7f90",
        "lessThan": "5289ac43b69c61a49c75720921f2008005a31c43",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "d5f7d3833b534f9e43e548461dba1e60aa82f587",
        "lessThan": "04c50cc23a492c4d43fdaefc7c1ecc0ff6f7b82e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ae6b01bafee8fa385aa25ee7ebdb40057f6abe",
        "lessThan": "806d5c1e1d2e5502175a24bf70f251648d99c36a",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ae6b01bafee8fa385aa25ee7ebdb40057f6abe",
        "lessThan": "79e140bba70bcacc5fe15bf8c0b958793fd7d56f",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ae6b01bafee8fa385aa25ee7ebdb40057f6abe",
        "lessThan": "900b444be493b7f404898c785d6605b177a093d0",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "93ae6b01bafee8fa385aa25ee7ebdb40057f6abe",
        "lessThan": "fbc7e61195e23f744814e78524b73b59faa54ab4",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "arch/arm64/kernel/fpsimd.c",
      "arch/arm64/kvm/fpsimd.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.2"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.2",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.85",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.21",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.13.9",
        "versionType": "semver",
        "lessThanOrEqual": "6.13.*"
      },
      {
        "status": "unaffected",
        "version": "6.14",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "arch/arm64/kernel/fpsimd.c",
      "arch/arm64/kvm/fpsimd.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2025-22013

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#30451 · Revision 1
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Publisher date
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