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CVE-2026-93125

Estado: RecibidaAlta (7.8)—

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

bpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max

check_kfunc_args() detects a kfunc argument named rdonly_buf_size or rdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64, and does not bound it. check_kfunc_call() later copies that value into the returned register's mem_size field:

regs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set gets truncated instead of causing a load-time rejection, so the verifier records a PTR_TO_MEM register with an approximately 4 GiB mem_size for whatever allocation the kfunc returned. A later access check against that register uses the truncated, wrong bound.

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Reject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the point meta->r0_size is set.

Detalles técnicos trazas, registros y código del informe original
  meta->r0_size = reg->var_off.value;
  ...
  regs[BPF_REG_0].mem_size = meta.r0_size;

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 (AV:L/PR:L) en verificador de eBPF del kernel que permite escalada mediante truncamiento de bounds en mem_size, causando acceso fuera de límites y potencial ejecución de código o DoS.

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

Execution PreventionThreat Intelligence ProgramRestrict Web-Based ContentFilter Network TrafficBehavior Prevention on EndpointDisable or Remove Feature or Program

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-2026-93125",
  "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": "eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae",
              "lessThan": "56a3846830ac95a472297d0cbba75cbff29540bb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "eb1f7f71c126c8fd50ea81af98f97c4b581ea4ae",
              "lessThan": "2aaf67f0516fde29620d0edfc29c01b9ea7ad430",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.1"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.1",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-17T17:18:07.247",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/2aaf67f0516fde29620d0edfc29c01b9ea7ad430",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/56a3846830ac95a472297d0cbba75cbff29540bb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject rdonly/rdwr_buf_size kfunc arguments that exceed u32 max\n\ncheck_kfunc_args() detects a kfunc argument named rdonly_buf_size or\nrdwr_buf_size and stores reg->var_off.value into meta->r0_size, a u64,\nand does not bound it. check_kfunc_call() later copies that value into\nthe returned register's mem_size field:\n\n  meta->r0_size = reg->var_off.value;\n  ...\n  regs[BPF_REG_0].mem_size = meta.r0_size;\n\nregs[BPF_REG_0].mem_size is u32. A constant whose upper 32 bits are set\ngets truncated instead of causing a load-time rejection, so the verifier\nrecords a PTR_TO_MEM register with an approximately 4 GiB mem_size for\nwhatever allocation the kfunc returned. A later access check against\nthat register uses the truncated, wrong bound.\n\nReject rdonly_buf_size/rdwr_buf_size values that exceed U32_MAX at the\npoint meta->r0_size is set."
    }
  ],
  "lastModified": "2026-09-18T18:18:21.907",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}