« Volver al listado

CVE-2026-68283

Estado: RecibidaAlta (8.8)—

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

tracing: Fix use-after-free freeing trigger private data

Commit 61d445af0a7c ("tracing: Add bulk garbage collection of freeing event_trigger_data") moved the kfree() of event_trigger_data to a kthread that runs tracepoint_synchronize_unregister() before freeing. That removed the synchronization the trigger .free callbacks used to get implicitly and inline from trigger_data_free().

event_hist_trigger_free(), event_hist_trigger_named_free() and event_enable_trigger_free() free their satellite data (hist_data, cmd_ops, enable_data) right after trigger_data_free() returns.

Leer descripción completaMostrar menos

With the synchronization now deferred to the kthread, a concurrent tracepoint handler can still reach that data through the list_del_rcu()'d trigger, causing a use-after-free.

The histogram teardown must stay synchronous: remove_hist_vars() and unregister_field_var_hists() have to detach a synthetic event from the histogram before the trigger-removal write returns, otherwise a following command races in and the synthetic-event removal fails with -EBUSY, as the trigger-synthetic-eprobe.tc selftest catches. Make those callbacks wait with the correct barrier - tracepoint_synchronize_unregister(), matching the free kthread - before freeing.

The enable trigger has no such synchronous requirement, and a blocking synchronize there would re-serialize the path that commit deliberately deferred. Give it an optional private_data_free() callback that the free kthread runs after its grace period, and free enable_data from there.

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 use-after-free en kernel de Linux que requiere PR:L (acceso autenticado a la red/sistema). T1068 por escalada de privilegios implícita al corromper memoria del kernel. T1499.004 por potencial DoS mediante crash del kernel.

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 ProgramApplication Isolation and SandboxingExploit ProtectionUpdate SoftwareVulnerability ScanningPrivileged Account Management

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)

Mostrar
{
  "id": "CVE-2026-68283",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/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": 2.8
      }
    ]
  },
  "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": "61d445af0a7c70018111919e47beaaee15653f2f",
              "lessThan": "b9c8a1400a3bf633f32820d184f3e05fed0f4af7",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "61d445af0a7c70018111919e47beaaee15653f2f",
              "lessThan": "79097812153b826fc156a2930ec8a90ed9edf4a2",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "kernel/trace/trace.h",
            "kernel/trace/trace_events_hist.c",
            "kernel/trace/trace_events_trigger.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.19"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.19",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "kernel/trace/trace.h",
            "kernel/trace/trace_events_hist.c",
            "kernel/trace/trace_events_trigger.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-10T13:20:17.563",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/79097812153b826fc156a2930ec8a90ed9edf4a2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b9c8a1400a3bf633f32820d184f3e05fed0f4af7",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix use-after-free freeing trigger private data\n\nCommit 61d445af0a7c (\"tracing: Add bulk garbage collection of freeing\nevent_trigger_data\") moved the kfree() of event_trigger_data to a kthread\nthat runs tracepoint_synchronize_unregister() before freeing. That removed\nthe synchronization the trigger .free callbacks used to get implicitly and\ninline from trigger_data_free().\n\nevent_hist_trigger_free(), event_hist_trigger_named_free() and\nevent_enable_trigger_free() free their satellite data (hist_data, cmd_ops,\nenable_data) right after trigger_data_free() returns. With the\nsynchronization now deferred to the kthread, a concurrent tracepoint\nhandler can still reach that data through the list_del_rcu()'d trigger,\ncausing a use-after-free.\n\nThe histogram teardown must stay synchronous: remove_hist_vars() and\nunregister_field_var_hists() have to detach a synthetic event from the\nhistogram before the trigger-removal write returns, otherwise a following\ncommand races in and the synthetic-event removal fails with -EBUSY, as the\ntrigger-synthetic-eprobe.tc selftest catches. Make those callbacks wait\nwith the correct barrier - tracepoint_synchronize_unregister(), matching\nthe free kthread - before freeing.\n\nThe enable trigger has no such synchronous requirement, and a blocking\nsynchronize there would re-serialize the path that commit deliberately\ndeferred. Give it an optional private_data_free() callback that the free\nkthread runs after its grace period, and free enable_data from there."
    }
  ],
  "lastModified": "2026-08-17T05:18:30.910",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}