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CVE-2026-72112

Estado: RecibidaAlta (7.8)—

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

io_uring/bpf-ops: reject re-registration of an already-bound ops

io_install_bpf() only rejects a second registration on the ctx side (ctx->bpf_ops) and sets the per-map back-pointer ops->priv unconditionally. The struct_ops link path never advances a map past BPF_STRUCT_OPS_STATE_READY, so the same io_uring_bpf_ops map can be registered more than once, and bpf_io_reg() re-resolves the target ring via fget(ops->ring_fd) on every call. A caller can therefore point the same ring_fd at a different io_ring_ctx between two BPF_LINK_CREATE calls.

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The second registration passes the ctx->bpf_ops check (the new ctx has none) and overwrites ops->priv, orphaning the first ctx. Teardown (io_eject_bpf()/bpf_io_unreg()) only reaches a ctx through ops->priv, so the orphaned ctx is never torn down: its ctx->loop_step keeps pointing into the struct_ops trampoline, which is freed once the map is gone. A later io_uring_enter() on the orphaned ring then calls the dangling ctx->loop_step from io_run_loop() -- a use-after-free of freed executable memory, reachable by a task with CAP_BPF + CAP_PERFMON.

Reject registration when ops->priv is already set, as hid_bpf_reg() does for its struct_ops.

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.

AV:L + PR:L + UI:N indica escalada local con privilegios bajos (CAP_BPF+CAP_PERFMON). Use-after-free en código ejecutable permite ejecución de código. El DoS por corrupción de memoria es secundario.

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

Tecnologías afectadas (1)

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

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-72112",
  "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": "98f37634b12b17ad5c56db8fb63cf9d7dc55d74c",
              "lessThan": "0639ea767fe04c288a8d6cb826100fe3d95d4936",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "98f37634b12b17ad5c56db8fb63cf9d7dc55d74c",
              "lessThan": "3afc64c61ce906a04f073ca350b46de10e8302f9",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "io_uring/bpf-ops.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "7.1",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "io_uring/bpf-ops.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T06:21:25.563",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0639ea767fe04c288a8d6cb826100fe3d95d4936",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3afc64c61ce906a04f073ca350b46de10e8302f9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/bpf-ops: reject re-registration of an already-bound ops\n\nio_install_bpf() only rejects a second registration on the ctx side\n(ctx->bpf_ops) and sets the per-map back-pointer ops->priv\nunconditionally. The struct_ops link path never advances a map past\nBPF_STRUCT_OPS_STATE_READY, so the same io_uring_bpf_ops map can be\nregistered more than once, and bpf_io_reg() re-resolves the target ring\nvia fget(ops->ring_fd) on every call. A caller can therefore point the\nsame ring_fd at a different io_ring_ctx between two BPF_LINK_CREATE\ncalls.\n\nThe second registration passes the ctx->bpf_ops check (the new ctx has\nnone) and overwrites ops->priv, orphaning the first ctx. Teardown\n(io_eject_bpf()/bpf_io_unreg()) only reaches a ctx through ops->priv, so\nthe orphaned ctx is never torn down: its ctx->loop_step keeps pointing\ninto the struct_ops trampoline, which is freed once the map is gone. A\nlater io_uring_enter() on the orphaned ring then calls the dangling\nctx->loop_step from io_run_loop() -- a use-after-free of freed\nexecutable memory, reachable by a task with CAP_BPF + CAP_PERFMON.\n\nReject registration when ops->priv is already set, as hid_bpf_reg()\ndoes for its struct_ops."
    }
  ],
  "lastModified": "2026-08-17T06:18:10.417",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}