CVE-2026-89747

Estado: RecibidaAlta (7.8)—

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

tracing: Fix use-after-free in trace_pipe read on sub-buffer order change

Writing to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(), which frees every sub-buffer of the ring buffer, including the reader page, and replaces them with newly allocated ones.

Readers of trace_pipe hold pointers into those pages. ring_buffer_peek() looks up an event under cpu_buffer->reader_lock but returns the event pointer after dropping the lock, and peek_next_entry() then calls ring_buffer_event_length() and ring_buffer_event_data() on it. If the sub-buffer order is changed in that window, the reader dereferences freed memory:

Leer descripción completaMostrar menos

Take trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change. This is the lock trace_pipe readers already hold across their entire peek-and-print loop, so the swap can no longer race with a reader that is dereferencing a peeked event.

Detalles técnicos trazas, registros y código del informe original

  BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0/0x430
  Read of size 1 at addr ffff88802a4cf010 by task syz-executor989/6002

  Freed by:
   free_buffer_page kernel/trace/ring_buffer.c:398 [inline]
   ring_buffer_subbuf_order_set+0x1325/0x18e0 kernel/trace/ring_buffer.c:7444
   buffer_subbuf_size_write+0x182/0x280 kernel/trace/trace.c:8221

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.16%
Percentil entre todas las CVEs puntuadas: 5
Fecha de la puntuación: 5/10/2026

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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1499.004 Application or System Exploitationimpact75 %
Impacto secundarioT1005 Data from Local Systemcollection60 %

Vulnerabilidad local (AV:L/PR:L) en kernel Linux que permite DoS por uso-después-liberación al cambiar buffer_subbuf_size_kb, causando lecturas de memoria liberada y potencial corrupción/acceso a datos 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 Program Filter Network Traffic Execution Prevention Application Isolation and Sandboxing Exploit Protection Update Software

Tecnologías afectadas (1)

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

Linux — Linux Kernel^AI

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-89747",
  "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": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
              "lessThan": "05ebe1e1d7d38c2612bacfefe043a33572ae34cb",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
              "lessThan": "ddbe921ed16a0ad2d9e09574c3f3aabec7528325",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
              "lessThan": "7a49d19ff9baaf61217e5ec14199c18bc2d93ee4",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f9b94daa542a8d2532f0930f01cd9aec2d19621b",
              "lessThan": "372f8534244d632ad5118e8a87a11291b01712d3",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "kernel/trace/trace.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.8"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.8",
              "versionType": "semver"
            },
            {
              "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": [
            "kernel/trace/trace.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:20:05.517",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/05ebe1e1d7d38c2612bacfefe043a33572ae34cb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/372f8534244d632ad5118e8a87a11291b01712d3",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7a49d19ff9baaf61217e5ec14199c18bc2d93ee4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ddbe921ed16a0ad2d9e09574c3f3aabec7528325",
      "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 in trace_pipe read on sub-buffer order change\n\nWriting to buffer_subbuf_size_kb calls ring_buffer_subbuf_order_set(),\nwhich frees every sub-buffer of the ring buffer, including the reader\npage, and replaces them with newly allocated ones.\n\nReaders of trace_pipe hold pointers into those pages. ring_buffer_peek()\nlooks up an event under cpu_buffer->reader_lock but returns the event\npointer after dropping the lock, and peek_next_entry() then calls\nring_buffer_event_length() and ring_buffer_event_data() on it. If the\nsub-buffer order is changed in that window, the reader dereferences\nfreed memory:\n\n  BUG: KASAN: use-after-free in ring_buffer_peek+0x3e0/0x430\n  Read of size 1 at addr ffff88802a4cf010 by task syz-executor989/6002\n\n  Freed by:\n   free_buffer_page kernel/trace/ring_buffer.c:398 [inline]\n   ring_buffer_subbuf_order_set+0x1325/0x18e0 kernel/trace/ring_buffer.c:7444\n   buffer_subbuf_size_write+0x182/0x280 kernel/trace/trace.c:8221\n\nTake trace_access_lock(RING_BUFFER_ALL_CPUS) around the order change.\nThis is the lock trace_pipe readers already hold across their entire\npeek-and-print loop, so the swap can no longer race with a reader that\nis dereferencing a peeked event."
    }
  ],
  "lastModified": "2026-09-13T07:17:39.363",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}