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CVE-2026-74584

Estado: RecibidaAlta (7.1)—

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

RDMA/bnxt_re: zero shared page before exposing to userspace

bnxt_re_alloc_ucontext() allocates uctx->shpg via __get_free_page(GFP_KERNEL). The buddy allocator does not zero pages without __GFP_ZERO, so the page contains stale kernel data from whatever object most recently freed it.

The page is then mapped into userspace via vm_insert_page() under BNXT_RE_MMAP_SH_PAGE in bnxt_re_mmap(). The driver only ever writes 4 bytes (a u32 AVID) at offset BNXT_RE_AVID_OFFT (0x10) inside bnxt_re_create_ah(); the remaining 4092 bytes of the page are exposed to userspace unsanitised, leaking kernel memory contents.

Leer descripción completaMostrar menos

Any user with access to /dev/infiniband/uverbsX on a host with a bnxt_re device (typically rdma group membership) can read this data via a single mmap() at pgoff 0 after IB_USER_VERBS_CMD_GET_CONTEXT.

Other shared pages in the same file already use get_zeroed_page() correctly:

uctx->shpg is the only outlier. Bring it in line with the existing convention by switching to get_zeroed_page().

Detalles técnicos trazas, registros y código del informe original
  drivers/infiniband/hw/bnxt_re/ib_verbs.c
      srq->uctx_srq_page = (void *)get_zeroed_page(GFP_KERNEL);
      cq->uctx_cq_page  = (void *)get_zeroed_page(GFP_KERNEL);

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.

Acceso local (AV:L) sin interacción de usuario permite leer datos kernel no inicializados desde la página compartida mapeada a userspace. El CWE se relaciona con falta de sanitización (liberación de memoria con datos sensibles).

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

User TrainingThreat Intelligence ProgramRestrict File and Directory PermissionsPassword PoliciesExecution PreventionAudit

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-2026-74584",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 7.1,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 4,
        "exploitabilityScore": 2.5
      }
    ]
  },
  "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": "1ac5a404797523cedaf424a3aaa3cf8f9548dff8",
              "lessThan": "53c97e9882f4e747b4ac31b211317c2eba541af9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1ac5a404797523cedaf424a3aaa3cf8f9548dff8",
              "lessThan": "9896bdfd21d918e9f26a52bc6109cc77970ee0b1",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1ac5a404797523cedaf424a3aaa3cf8f9548dff8",
              "lessThan": "9128c2411b83a64c0a69d2ff059c741bde25a9cc",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1ac5a404797523cedaf424a3aaa3cf8f9548dff8",
              "lessThan": "c19b360fa10c521c0b681875cdaa51545d45a491",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1ac5a404797523cedaf424a3aaa3cf8f9548dff8",
              "lessThan": "a3ed2daab02b2a706e882ad31b5c3c4f33cb5bb1",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1ac5a404797523cedaf424a3aaa3cf8f9548dff8",
              "lessThan": "e2b143df29003d2704b51f62e9297006953dbacb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1ac5a404797523cedaf424a3aaa3cf8f9548dff8",
              "lessThan": "c75f8ce4baa29ae57fe615c6a2c5101f59b8b89a",
              "versionType": "git"
            },
            {
              "status": "affected",
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              "lessThan": "f6b079629becfa977f9c51fe53ad2e6dcc55ef44",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/infiniband/hw/bnxt_re/ib_verbs.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.11"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "4.11",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.260",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.211",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.177",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.144",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.95",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.37",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.0.14",
              "versionType": "semver",
              "lessThanOrEqual": "7.0.*"
            },
            {
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/infiniband/hw/bnxt_re/ib_verbs.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-22T15:16:21.230",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/53c97e9882f4e747b4ac31b211317c2eba541af9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9128c2411b83a64c0a69d2ff059c741bde25a9cc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9896bdfd21d918e9f26a52bc6109cc77970ee0b1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a3ed2daab02b2a706e882ad31b5c3c4f33cb5bb1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c19b360fa10c521c0b681875cdaa51545d45a491",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c75f8ce4baa29ae57fe615c6a2c5101f59b8b89a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e2b143df29003d2704b51f62e9297006953dbacb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f6b079629becfa977f9c51fe53ad2e6dcc55ef44",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/bnxt_re: zero shared page before exposing to userspace\n\nbnxt_re_alloc_ucontext() allocates uctx->shpg via\n__get_free_page(GFP_KERNEL). The buddy allocator does not zero pages\nwithout __GFP_ZERO, so the page contains stale kernel data from\nwhatever object most recently freed it.\n\nThe page is then mapped into userspace via vm_insert_page() under\nBNXT_RE_MMAP_SH_PAGE in bnxt_re_mmap(). The driver only ever writes\n4 bytes (a u32 AVID) at offset BNXT_RE_AVID_OFFT (0x10) inside\nbnxt_re_create_ah(); the remaining 4092 bytes of the page are exposed\nto userspace unsanitised, leaking kernel memory contents.\n\nAny user with access to /dev/infiniband/uverbsX on a host with a\nbnxt_re device (typically rdma group membership) can read this data\nvia a single mmap() at pgoff 0 after IB_USER_VERBS_CMD_GET_CONTEXT.\n\nOther shared pages in the same file already use get_zeroed_page()\ncorrectly:\n\n  drivers/infiniband/hw/bnxt_re/ib_verbs.c\n      srq->uctx_srq_page = (void *)get_zeroed_page(GFP_KERNEL);\n      cq->uctx_cq_page  = (void *)get_zeroed_page(GFP_KERNEL);\n\nuctx->shpg is the only outlier. Bring it in line with the existing\nconvention by switching to get_zeroed_page()."
    }
  ],
  "lastModified": "2026-08-25T06:18:32.357",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}