CVE-2025-22013 (GCVE-0-2025-22013)
Vulnerability from cvelistv5
Published
2025-04-08 08:18
Modified
2025-04-25 10:06
Severity ?
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/79e140bba70bcacc5fe15bf8c0b958793fd7d56f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/806d5c1e1d2e5502175a24bf70f251648d99c36a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/900b444be493b7f404898c785d6605b177a093d0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fbc7e61195e23f744814e78524b73b59faa54ab4
Impacted products
Vendor Product Version
Linux Linux Version: d5f7d3833b534f9e43e548461dba1e60aa82f587
Version: 93ae6b01bafee8fa385aa25ee7ebdb40057f6abe
Version: 93ae6b01bafee8fa385aa25ee7ebdb40057f6abe
Version: 93ae6b01bafee8fa385aa25ee7ebdb40057f6abe
Version: 93ae6b01bafee8fa385aa25ee7ebdb40057f6abe
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   Linux Linux Version: 6.2
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kernel/fpsimd.c",
            "arch/arm64/kvm/fpsimd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "04c50cc23a492c4d43fdaefc7c1ecc0ff6f7b82e",
              "status": "affected",
              "version": "d5f7d3833b534f9e43e548461dba1e60aa82f587",
              "versionType": "git"
            },
            {
              "lessThan": "806d5c1e1d2e5502175a24bf70f251648d99c36a",
              "status": "affected",
              "version": "93ae6b01bafee8fa385aa25ee7ebdb40057f6abe",
              "versionType": "git"
            },
            {
              "lessThan": "79e140bba70bcacc5fe15bf8c0b958793fd7d56f",
              "status": "affected",
              "version": "93ae6b01bafee8fa385aa25ee7ebdb40057f6abe",
              "versionType": "git"
            },
            {
              "lessThan": "900b444be493b7f404898c785d6605b177a093d0",
              "status": "affected",
              "version": "93ae6b01bafee8fa385aa25ee7ebdb40057f6abe",
              "versionType": "git"
            },
            {
              "lessThan": "fbc7e61195e23f744814e78524b73b59faa54ab4",
              "status": "affected",
              "version": "93ae6b01bafee8fa385aa25ee7ebdb40057f6abe",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/arm64/kernel/fpsimd.c",
            "arch/arm64/kvm/fpsimd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.2"
            },
            {
              "lessThan": "6.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.85",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.21",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.13.*",
              "status": "unaffected",
              "version": "6.13.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.14",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state\n\nThere are several problems with the way hyp code lazily saves the host\u0027s\nFPSIMD/SVE state, including:\n\n* Host SVE being discarded unexpectedly due to inconsistent\n  configuration of TIF_SVE and CPACR_ELx.ZEN. This has been seen to\n  result in QEMU crashes where SVE is used by memmove(), as reported by\n  Eric Auger:\n\n  https://issues.redhat.com/browse/RHEL-68997\n\n* Host SVE state is discarded *after* modification by ptrace, which was an\n  unintentional ptrace ABI change introduced with lazy discarding of SVE state.\n\n* The host FPMR value can be discarded when running a non-protected VM,\n  where FPMR support is not exposed to a VM, and that VM uses\n  FPSIMD/SVE. In these cases the hyp code does not save the host\u0027s FPMR\n  before unbinding the host\u0027s FPSIMD/SVE/SME state, leaving a stale\n  value in memory.\n\nAvoid these by eagerly saving and \"flushing\" the host\u0027s FPSIMD/SVE/SME\nstate when loading a vCPU such that KVM does not need to save any of the\nhost\u0027s FPSIMD/SVE/SME state. For clarity, fpsimd_kvm_prepare() is\nremoved and the necessary call to fpsimd_save_and_flush_cpu_state() is\nplaced in kvm_arch_vcpu_load_fp(). As \u0027fpsimd_state\u0027 and \u0027fpmr_ptr\u0027\nshould not be used, they are set to NULL; all uses of these will be\nremoved in subsequent patches.\n\nHistorical problems go back at least as far as v5.17, e.g. erroneous\nassumptions about TIF_SVE being clear in commit:\n\n  8383741ab2e773a9 (\"KVM: arm64: Get rid of host SVE tracking/saving\")\n\n... and so this eager save+flush probably needs to be backported to ALL\nstable trees."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-04-25T10:06:45.938Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/04c50cc23a492c4d43fdaefc7c1ecc0ff6f7b82e"
        },
        {
          "url": "https://git.kernel.org/stable/c/806d5c1e1d2e5502175a24bf70f251648d99c36a"
        },
        {
          "url": "https://git.kernel.org/stable/c/79e140bba70bcacc5fe15bf8c0b958793fd7d56f"
        },
        {
          "url": "https://git.kernel.org/stable/c/900b444be493b7f404898c785d6605b177a093d0"
        },
        {
          "url": "https://git.kernel.org/stable/c/fbc7e61195e23f744814e78524b73b59faa54ab4"
        }
      ],
      "title": "KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state",
      "x_generator": {
        "engine": "bippy-1.1.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-22013",
    "datePublished": "2025-04-08T08:18:04.000Z",
    "dateReserved": "2024-12-29T08:45:45.806Z",
    "dateUpdated": "2025-04-25T10:06:45.938Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-22013\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-04-08T09:15:25.643\",\"lastModified\":\"2025-04-08T18:13:53.347\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nKVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state\\n\\nThere are several problems with the way hyp code lazily saves the host\u0027s\\nFPSIMD/SVE state, including:\\n\\n* Host SVE being discarded unexpectedly due to inconsistent\\n  configuration of TIF_SVE and CPACR_ELx.ZEN. This has been seen to\\n  result in QEMU crashes where SVE is used by memmove(), as reported by\\n  Eric Auger:\\n\\n  https://issues.redhat.com/browse/RHEL-68997\\n\\n* Host SVE state is discarded *after* modification by ptrace, which was an\\n  unintentional ptrace ABI change introduced with lazy discarding of SVE state.\\n\\n* The host FPMR value can be discarded when running a non-protected VM,\\n  where FPMR support is not exposed to a VM, and that VM uses\\n  FPSIMD/SVE. In these cases the hyp code does not save the host\u0027s FPMR\\n  before unbinding the host\u0027s FPSIMD/SVE/SME state, leaving a stale\\n  value in memory.\\n\\nAvoid these by eagerly saving and \\\"flushing\\\" the host\u0027s FPSIMD/SVE/SME\\nstate when loading a vCPU such that KVM does not need to save any of the\\nhost\u0027s FPSIMD/SVE/SME state. For clarity, fpsimd_kvm_prepare() is\\nremoved and the necessary call to fpsimd_save_and_flush_cpu_state() is\\nplaced in kvm_arch_vcpu_load_fp(). As \u0027fpsimd_state\u0027 and \u0027fpmr_ptr\u0027\\nshould not be used, they are set to NULL; all uses of these will be\\nremoved in subsequent patches.\\n\\nHistorical problems go back at least as far as v5.17, e.g. erroneous\\nassumptions about TIF_SVE being clear in commit:\\n\\n  8383741ab2e773a9 (\\\"KVM: arm64: Get rid of host SVE tracking/saving\\\")\\n\\n... and so this eager save+flush probably needs to be backported to ALL\\nstable trees.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: KVM: arm64: Guardar y vaciar incondicionalmente el estado FPSIMD/SVE/SME del host Hay varios problemas con la forma en que el c\u00f3digo hyp guarda de forma diferida el estado FPSIMD/SVE del host, incluidos: * El SVE del host se descarta inesperadamente debido a una configuraci\u00f3n inconsistente de TIF_SVE y CPACR_ELx.ZEN. Se ha visto que esto da como resultado fallos de QEMU donde memmove() usa SVE, como lo inform\u00f3 Eric Auger: https://issues.redhat.com/browse/RHEL-68997 * El estado SVE del host se descarta *despu\u00e9s* de la modificaci\u00f3n por ptrace, que fue un cambio de ABI de ptrace no intencionado introducido con el descarte diferido del estado SVE. * El valor FPMR del host se puede descartar cuando se ejecuta una VM no protegida, donde la compatibilidad con FPMR no est\u00e1 expuesta a una VM y esa VM usa FPSIMD/SVE. En estos casos, el c\u00f3digo hyp no guarda el FPMR del host antes de desvincular su estado FPSIMD/SVE/SME, lo que deja un valor obsoleto en memoria. Para evitar esto, guarde y vac\u00ede el estado FPSIMD/SVE/SME del host al cargar una vCPU, de modo que KVM no tenga que guardar ninguno de sus estados. Para mayor claridad, se ha eliminado fpsimd_kvm_prepare() y la llamada necesaria a fpsimd_save_and_flush_cpu_state() se ha ubicado en kvm_arch_vcpu_load_fp(). Dado que \u0027fpsimd_state\u0027 y \u0027fpmr_ptr\u0027 no deben usarse, se establecen en NULL; todos sus usos se eliminar\u00e1n en parches posteriores. Los problemas hist\u00f3ricos se remontan al menos a la versi\u00f3n v5.17, por ejemplo, suposiciones err\u00f3neas acerca de que TIF_SVE est\u00e1 claro en el commit: 8383741ab2e773a9 (\\\"KVM: arm64: deshacerse del seguimiento/guardado de SVE del host\\\")... y por eso, este ansioso guardado y vaciado probablemente deba ser retrotra\u00eddo a TODOS los \u00e1rboles estables.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/79e140bba70bcacc5fe15bf8c0b958793fd7d56f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/806d5c1e1d2e5502175a24bf70f251648d99c36a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/900b444be493b7f404898c785d6605b177a093d0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fbc7e61195e23f744814e78524b73b59faa54ab4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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