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CVE-2022-49726

Estado: AnalizadaMedia (5.5)—

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

clocksource: hyper-v: unexport __init-annotated hv_init_clocksource()

EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic.

modpost used to detect it, but it has been broken for a decade.

Recently, I fixed modpost so it started to warn it again, then this showed up in linux-next builds.

There are two ways to fix it:

I chose the latter for this case because the only in-tree call-site, arch/x86/kernel/cpu/mshyperv.c is never compiled as modular. (CONFIG_HYPERVISOR_GUEST is boolean)

Detalles técnicos trazas, registros y código del informe original
  - Remove __init
  - Remove EXPORT_SYMBOL

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2022-49726",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
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        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 5.5,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 1.8
      }
    ]
  },
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          "product": "Linux",
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          "programFiles": [
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        {
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          "vendor": "Linux",
          "product": "Linux",
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              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
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          ],
          "programFiles": [
            "drivers/clocksource/hyperv_timer.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-02-26T07:01:48.257",
  "references": [
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      "url": "https://git.kernel.org/stable/c/0414eab7c78f3518143d383e448d44fc573ac6d2",
      "tags": [
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      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/245b993d8f6c4e25f19191edfbd8080b645e12b1",
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "tags": [
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-908"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nclocksource: hyper-v: unexport __init-annotated hv_init_clocksource()\n\nEXPORT_SYMBOL and __init is a bad combination because the .init.text\nsection is freed up after the initialization. Hence, modules cannot\nuse symbols annotated __init. The access to a freed symbol may end up\nwith kernel panic.\n\nmodpost used to detect it, but it has been broken for a decade.\n\nRecently, I fixed modpost so it started to warn it again, then this\nshowed up in linux-next builds.\n\nThere are two ways to fix it:\n\n  - Remove __init\n  - Remove EXPORT_SYMBOL\n\nI chose the latter for this case because the only in-tree call-site,\narch/x86/kernel/cpu/mshyperv.c is never compiled as modular.\n(CONFIG_HYPERVISOR_GUEST is boolean)"
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: clocksource: hyper-v: unexport __init-annotated hv_init_clocksource() EXPORT_SYMBOL y __init es una mala combinación porque la sección .init.text se libera después de la inicialización. Por lo tanto, los módulos no pueden usar símbolos anotados __init. El acceso a un símbolo liberado puede terminar con un pánico del kernel. modpost solía detectarlo, pero ha estado roto durante una década. Recientemente, arreglé modpost para que comenzara a advertirlo nuevamente, luego apareció en las compilaciones de linux-next. Hay dos formas de solucionarlo: - Eliminar __init - Eliminar EXPORT_SYMBOL Elegí la última para este caso porque el único sitio de llamada en el árbol, arch/x86/kernel/cpu/mshyperv.c nunca se compila como modular. (CONFIG_HYPERVISOR_GUEST es booleano)"
    }
  ],
  "lastModified": "2026-06-17T05:18:58.783",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
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}