CVE-2022-49081

Estado: AnalizadaMedia (5.5)—

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

When CONFIG_DEBUG_KMAP_LOCAL is enabled __kmap_local_sched_{in,out} check that even slots in the tsk->kmap_ctrl.pteval are unmapped. The slots are initialized with 0 value, but the check is done with pte_none. 0 pte however does not necessarily mean that pte_none will return true. e.g. on xtensa it returns false, resulting in the following runtime warnings:

Fix it by replacing !pte_none(pteval) with pte_val(pteval) != 0.

Detalles técnicos trazas, registros y código del informe original

highmem: fix checks in __kmap_local_sched_{in,out}

 WARNING: CPU: 0 PID: 101 at mm/highmem.c:627 __kmap_local_sched_out+0x51/0x108
 CPU: 0 PID: 101 Comm: touch Not tainted 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13
 Call Trace:
   dump_stack+0xc/0x40
   __warn+0x8f/0x174
   warn_slowpath_fmt+0x48/0xac
   __kmap_local_sched_out+0x51/0x108
   __schedule+0x71a/0x9c4
   preempt_schedule_irq+0xa0/0xe0
   common_exception_return+0x5c/0x93
   do_wp_page+0x30e/0x330
   handle_mm_fault+0xa70/0xc3c
   do_page_fault+0x1d8/0x3c4
   common_exception+0x7f/0x7f

 WARNING: CPU: 0 PID: 101 at mm/highmem.c:664 __kmap_local_sched_in+0x50/0xe0
 CPU: 0 PID: 101 Comm: touch Tainted: G        W         5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13
 Call Trace:
   dump_stack+0xc/0x40
   __warn+0x8f/0x174
   warn_slowpath_fmt+0x48/0xac
   __kmap_local_sched_in+0x50/0xe0
   finish_task_switch$isra$0+0x1ce/0x2f8
   __schedule+0x86e/0x9c4
   preempt_schedule_irq+0xa0/0xe0
   common_exception_return+0x5c/0x93
   do_wp_page+0x30e/0x330
   handle_mm_fault+0xa70/0xc3c
   do_page_fault+0x1d8/0x3c4
   common_exception+0x7f/0x7f

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Puntuación base: 5.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.25%
Percentil entre todas las CVEs puntuadas: 15
Fecha de la puntuación: 6/10/2026

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)

Linux — Linux Kernel

CWE

NVD-CWE-noinfo

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2022-49081",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "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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      "affectedData": [
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          "vendor": "Linux",
          "product": "Linux",
          "versions": [
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              "status": "affected",
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          "defaultStatus": "unaffected"
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          "product": "Linux",
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              "version": "5.11"
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            {
              "status": "unaffected",
              "version": "0",
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              "status": "unaffected",
              "version": "5.15.34",
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              "status": "unaffected",
              "version": "5.16.20",
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              "version": "5.17.3",
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            },
            {
              "status": "unaffected",
              "version": "5.18",
              "versionType": "original_commit_for_fix",
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          ],
          "programFiles": [
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          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-02-26T07:00:45.450",
  "references": [
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      "tags": [
        "Patch"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nhighmem: fix checks in __kmap_local_sched_{in,out}\n\nWhen CONFIG_DEBUG_KMAP_LOCAL is enabled __kmap_local_sched_{in,out} check\nthat even slots in the tsk->kmap_ctrl.pteval are unmapped.  The slots are\ninitialized with 0 value, but the check is done with pte_none.  0 pte\nhowever does not necessarily mean that pte_none will return true.  e.g.\non xtensa it returns false, resulting in the following runtime warnings:\n\n WARNING: CPU: 0 PID: 101 at mm/highmem.c:627 __kmap_local_sched_out+0x51/0x108\n CPU: 0 PID: 101 Comm: touch Not tainted 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13\n Call Trace:\n   dump_stack+0xc/0x40\n   __warn+0x8f/0x174\n   warn_slowpath_fmt+0x48/0xac\n   __kmap_local_sched_out+0x51/0x108\n   __schedule+0x71a/0x9c4\n   preempt_schedule_irq+0xa0/0xe0\n   common_exception_return+0x5c/0x93\n   do_wp_page+0x30e/0x330\n   handle_mm_fault+0xa70/0xc3c\n   do_page_fault+0x1d8/0x3c4\n   common_exception+0x7f/0x7f\n\n WARNING: CPU: 0 PID: 101 at mm/highmem.c:664 __kmap_local_sched_in+0x50/0xe0\n CPU: 0 PID: 101 Comm: touch Tainted: G        W         5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13\n Call Trace:\n   dump_stack+0xc/0x40\n   __warn+0x8f/0x174\n   warn_slowpath_fmt+0x48/0xac\n   __kmap_local_sched_in+0x50/0xe0\n   finish_task_switch$isra$0+0x1ce/0x2f8\n   __schedule+0x86e/0x9c4\n   preempt_schedule_irq+0xa0/0xe0\n   common_exception_return+0x5c/0x93\n   do_wp_page+0x30e/0x330\n   handle_mm_fault+0xa70/0xc3c\n   do_page_fault+0x1d8/0x3c4\n   common_exception+0x7f/0x7f\n\nFix it by replacing !pte_none(pteval) with pte_val(pteval) != 0."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: highmem: se corrigen las comprobaciones en __kmap_local_sched_{in,out}. Cuando CONFIG_DEBUG_KMAP_LOCAL está habilitado, __kmap_local_sched_{in,out} comprueba que ni siquiera las ranuras en tsk-&gt;kmap_ctrl.pteval estén asignadas. Las ranuras se inicializan con el valor 0, pero la comprobación se realiza con pte_none. Sin embargo, 0 pte no significa necesariamente que pte_none devuelva verdadero. p. ej. en xtensa devuelve falso, lo que genera las siguientes advertencias de tiempo de ejecución: ADVERTENCIA: CPU: 0 PID: 101 en mm/highmem.c:627 __kmap_local_sched_out+0x51/0x108 CPU: 0 PID: 101 Comm: touch No contaminado 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13 Seguimiento de llamadas: dump_stack+0xc/0x40 __warn+0x8f/0x174 warn_slowpath_fmt+0x48/0xac __kmap_local_sched_out+0x51/0x108 __schedule+0x71a/0x9c4 preempt_schedule_irq+0xa0/0xe0 common_exception_return+0x5c/0x93 do_wp_page+0x30e/0x330 handle_mm_fault+0xa70/0xc3c do_page_fault+0x1d8/0x3c4 common_exception+0x7f/0x7f ADVERTENCIA: CPU: 0 PID: 101 en mm/highmem.c:664 __kmap_local_sched_in+0x50/0xe0 CPU: 0 PID: 101 Comm: toque Contaminado: GW 5.17.0-rc7-00010-gd3a1cdde80d2-dirty #13 Seguimiento de llamadas: dump_stack+0xc/0x40 __warn+0x8f/0x174 warn_slowpath_fmt+0x48/0xac __kmap_local_sched_in+0x50/0xe0 Soluciónelo reemplazando !pte_none(pteval) con pte_val(pteval) != 0."
    }
  ],
  "lastModified": "2026-06-17T05:17:01.663",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
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}