CVE-2025-40245

{
  "id": "CVE-2025-40245",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2025-12-04T16:16:17.827",
  "lastModified": "2026-10-19T19:10:00.130",
  "vulnStatus": "Deferred",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnios2: ensure that memblock.current_limit is set when setting pfn limits\n\nOn nios2, with CONFIG_FLATMEM set, the kernel relies on\nmemblock_get_current_limit() to determine the limits of mem_map, in\nparticular for max_low_pfn.\nUnfortunately, memblock.current_limit is only default initialized to\nMEMBLOCK_ALLOC_ANYWHERE at this point of the bootup, potentially leading\nto situations where max_low_pfn can erroneously exceed the value of\nmax_pfn and, thus, the valid range of available DRAM.\n\nThis can in turn cause kernel-level paging failures, e.g.:\n\n[   76.900000] Unable to handle kernel paging request at virtual address 20303000\n[   76.900000] ea = c0080890, ra = c000462c, cause = 14\n[   76.900000] Kernel panic - not syncing: Oops\n[   76.900000] ---[ end Kernel panic - not syncing: Oops ]---\n\nThis patch fixes this by pre-calculating memblock.current_limit\nbased on the upper limits of the available memory ranges via\nadjust_lowmem_bounds, a simplified version of the equivalent\nimplementation within the arm architecture."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nnios2: asegurar que memblock.current_limit esté configurado al establecer los límites de pfn\n\nEn nios2, con CONFIG_FLATMEM configurado, el kernel se basa en memblock_get_current_limit() para determinar los límites de mem_map, en particular para max_low_pfn.\nDesafortunadamente, memblock.current_limit solo se inicializa por defecto a MEMBLOCK_ALLOC_ANYWHERE en este punto del arranque, lo que puede llevar a situaciones en las que max_low_pfn puede exceder erróneamente el valor de max_pfn y, por lo tanto, el rango válido de DRAM disponible.\n\nEsto a su vez puede causar fallos de paginación a nivel de kernel, por ejemplo:\n\n[   76.900000] Unable to handle kernel paging request at virtual address 20303000\n[   76.900000] ea = c0080890, ra = c000462c, cause = 14\n[   76.900000] Kernel panic - not syncing: Oops\n[   76.900000] ---[ end Kernel panic - not syncing: Oops ]---\n\nEste parche soluciona esto precalculando memblock.current_limit basándose en los límites superiores de los rangos de memoria disponibles a través de adjust_lowmem_bounds, una versión simplificada de la implementación equivalente dentro de la arquitectura arm."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "arch/nios2/kernel/setup.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7f7bc20bc41a4fbcd2db75b375ac95e5faf958ae",
              "lessThan": "25f09699edd360b534ccae16bc276c3b52c471f3",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "7f7bc20bc41a4fbcd2db75b375ac95e5faf958ae",
              "lessThan": "5c3e38a367822f036227dd52bac82dc4a05157e2",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "7f7bc20bc41a4fbcd2db75b375ac95e5faf958ae",
              "lessThan": "b1ec9faef7e36269ca3ec890972a78effbaeb975",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "7f7bc20bc41a4fbcd2db75b375ac95e5faf958ae",
              "lessThan": "90f5f715550e07cd6a51f80fc3f062d832c8c997",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "7f7bc20bc41a4fbcd2db75b375ac95e5faf958ae",
              "lessThan": "8912814f14e298b83df072fecc1f7ed1b63b1b2c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "7f7bc20bc41a4fbcd2db75b375ac95e5faf958ae",
              "lessThan": "a20b83cf45be2057f3d073506779e52c7fa17f94",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "arch/nios2/kernel/setup.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.12",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.12",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.196",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.158",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.115",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.56",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.17.6",
              "lessThanOrEqual": "6.17.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/25f09699edd360b534ccae16bc276c3b52c471f3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5c3e38a367822f036227dd52bac82dc4a05157e2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8912814f14e298b83df072fecc1f7ed1b63b1b2c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/90f5f715550e07cd6a51f80fc3f062d832c8c997",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a20b83cf45be2057f3d073506779e52c7fa17f94",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b1ec9faef7e36269ca3ec890972a78effbaeb975",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}