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CVE-2026-89557

Estado: RecibidaAlta (7.8)—

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

md: do overflow check for sb->bblog_shift in super_1_load()

In super_1_load(), sb->bblog_shift is an __u8 type value loaded from on- disk superblock. It is used for badblocks API badblocks_set() by the following sequence,

bb->bblog_shit is in range of 0-255, variable sector is 64bit width, for an invalid bb->bblog_shit, it is possible to make sector be overflowed by the following calculation, 1935 sector <<= sb->bblog_shift; Then in turn when call badblocks_set() at line 1939 with the invalid rdev->badblocks.shift set at line 1930, may result an overflow inside _badblocks_clear() in block/badblocks.c.

Leer descripción completaMostrar menos

Although there are many places to call badblocks APIs, the non-zero shift value is only used in super_1_load(), other places always use 0 as the shift value. Therefore it is unnecessary to do a general shift value overflow check inside badblock API, and just check here as the caller.

This may avoid unnecessary check, make the badblocks API code more simple and elegant.

Detalles técnicos trazas, registros y código del informe original
 1930   rdev->badblocks.shift = sb->bblog_shift;
 1931   for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {
 1932           u64 bb = le64_to_cpu(*bbp);
 1933           int count = bb & (0x3ff);
 1934           u64 sector = bb >> 10;
 1935           sector <<= sb->bblog_shift;
 1936           count <<= sb->bblog_shift;
 1937           if (bb + 1 == 0)
 1938                   break;
 1939           if (!badblocks_set(&rdev->badblocks, sector, count, 1))
 1940                   return -EINVAL;
 1941   }

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).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vulnerabilidad local con PR:L que permite overflow de enteros en el kernel Linux. AV:L y PR:L indican escalada de privilegios. El overflow en sector/count puede causar DoS o corrupción de datos en badblocks.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Threat Intelligence ProgramRestrict File and Directory PermissionsRemote Data StorageFilter Network TrafficExecution PreventionEncrypt Sensitive Information

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux KernelAI

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-89557",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2699b67223aca6b1450fc2f72e40fada952afc85",
              "lessThan": "94c820d99a4305d4ded41a97ed37ec7d26c56e7f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2699b67223aca6b1450fc2f72e40fada952afc85",
              "lessThan": "573fb68105fdc6a127ba6069e58a0d2aff3c9f93",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2699b67223aca6b1450fc2f72e40fada952afc85",
              "lessThan": "323f3a056dbccb39a642ebde642044a680f3a6d6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2699b67223aca6b1450fc2f72e40fada952afc85",
              "lessThan": "0a03f9541c06fda64301dcf94f376f07ce2cc396",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2699b67223aca6b1450fc2f72e40fada952afc85",
              "lessThan": "75d15738fd33a782606d0dc80cfeff47edf2ddd8",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2699b67223aca6b1450fc2f72e40fada952afc85",
              "lessThan": "3b097416b4cff77285c1f472fc2c4058d8a7554f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2699b67223aca6b1450fc2f72e40fada952afc85",
              "lessThan": "df7d4d011d5ace20699ea948712f09f9ac08924f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2699b67223aca6b1450fc2f72e40fada952afc85",
              "lessThan": "35d522bd32462afcf1981dab6da8a9256c26c1e0",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/md/md.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.1"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "3.1",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.270",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.221",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.109",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/md/md.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:19:39.403",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0a03f9541c06fda64301dcf94f376f07ce2cc396",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/323f3a056dbccb39a642ebde642044a680f3a6d6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/35d522bd32462afcf1981dab6da8a9256c26c1e0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3b097416b4cff77285c1f472fc2c4058d8a7554f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/573fb68105fdc6a127ba6069e58a0d2aff3c9f93",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/75d15738fd33a782606d0dc80cfeff47edf2ddd8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/94c820d99a4305d4ded41a97ed37ec7d26c56e7f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/df7d4d011d5ace20699ea948712f09f9ac08924f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmd: do overflow check for sb->bblog_shift in super_1_load()\n\nIn super_1_load(), sb->bblog_shift is an __u8 type value loaded from on-\ndisk superblock. It is used for badblocks API badblocks_set() by the\nfollowing sequence,\n\n 1930   rdev->badblocks.shift = sb->bblog_shift;\n 1931   for (i = 0 ; i < (sectors << (9-3)) ; i++, bbp++) {\n 1932           u64 bb = le64_to_cpu(*bbp);\n 1933           int count = bb & (0x3ff);\n 1934           u64 sector = bb >> 10;\n 1935           sector <<= sb->bblog_shift;\n 1936           count <<= sb->bblog_shift;\n 1937           if (bb + 1 == 0)\n 1938                   break;\n 1939           if (!badblocks_set(&rdev->badblocks, sector, count, 1))\n 1940                   return -EINVAL;\n 1941   }\n\nbb->bblog_shit is in range of 0-255, variable sector is 64bit width, for\nan invalid bb->bblog_shit, it is possible to make sector be overflowed\nby the following calculation,\n 1935           sector <<= sb->bblog_shift;\nThen in turn when call badblocks_set() at line 1939 with the invalid\nrdev->badblocks.shift set at line 1930, may result an overflow inside\n_badblocks_clear() in block/badblocks.c.\n\nAlthough there are many places to call badblocks APIs, the non-zero\nshift value is only used in super_1_load(), other places always use 0 as\nthe shift value. Therefore it is unnecessary to do a general shift value\noverflow check inside badblock API, and just check here as the caller.\n\nThis may avoid unnecessary check, make the badblocks API code more simple\nand elegant."
    }
  ],
  "lastModified": "2026-09-14T13:19:10.773",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}