CVE-2026-74479

Estado: RecibidaAlta (7.8)—

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

net: pktgen: fix proc entry use-after-free

pktgen_change_name() replaces pkt_dev->entry while holding t->if_lock. pktgen_remove_device() removes the same entry before _rem_dev_from_if_list() takes that lock.

This allows the following interleaving:

The kthread can pass the stale proc_dir_entry to proc_remove() after the rename path has freed it. A reproducer with a widened race window reports:

Move proc_remove() into the if_lock-protected list removal helper. Keep it before list_del_rcu() to preserve the ordering required by add_device(). The rename path must then finish replacing the entry before removal, or it observes that the device is no longer on the list.

Detalles técnicos trazas, registros y código del informe original

  CPU 0 (NETDEV_CHANGENAME)       CPU 1 (kpktgend)
  if_lock(t)
  proc_remove(pkt_dev->entry)
                                  proc_remove(pkt_dev->entry)
  pkt_dev->entry = proc_create_data(...)
  if_unlock(t)

  BUG: KASAN: slab-use-after-free in proc_remove+0x78/0x80
  Read of size 8 at addr ffff8881478fea70 by task kpktgend_0/67
  Call Trace:
   proc_remove+0x78/0x80
   pktgen_remove_device.isra.0+0x11c/0x4c0
   pktgen_thread_worker+0x1214/0x6bc0
   kthread+0x2c6/0x3b0
  Allocated by task 95:
   __proc_create+0x204/0x790
   proc_create_data+0x72/0xe0
   pktgen_thread_write+0xd61/0x1510
  Freed by task 28:
   kmem_cache_free+0xcb/0x3d0
   proc_free_inode+0x5b/0x80
   rcu_core+0x50a/0x1850
  The buggy address belongs to the object at ffff8881478fea00
   which belongs to the cache proc_dir_entry of size 192

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: 0.13%
Percentil entre todas las CVEs puntuadas: 2
Fecha de la puntuación: 6/10/2026

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 %

Vulnerabilidad de use-after-free en kernel Linux (AV:L, PR:L) explotable localmente para escalada (T1068). El bug causa crash/DoS al ejecutar proc_remove() sobre memoria liberada (KASAN slab-use-after-free).

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-2026-74479",
  "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"
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        "exploitabilityScore": 1.8
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              "version": "5.15.217",
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              "version": "6.1.184",
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              "version": "6.6.153",
              "versionType": "semver",
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            },
            {
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              "version": "6.12.105",
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            {
              "status": "unaffected",
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              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/core/pktgen.c"
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        }
      ]
    }
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  "published": "2026-08-15T13:17:52.713",
  "references": [
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      "url": "https://git.kernel.org/stable/c/4ef801b838d85c0ea5852c50667f7344ce3b6cd0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: pktgen: fix proc entry use-after-free\n\npktgen_change_name() replaces pkt_dev->entry while holding t->if_lock.\npktgen_remove_device() removes the same entry before\n_rem_dev_from_if_list() takes that lock.\n\nThis allows the following interleaving:\n\n  CPU 0 (NETDEV_CHANGENAME)       CPU 1 (kpktgend)\n  if_lock(t)\n  proc_remove(pkt_dev->entry)\n                                  proc_remove(pkt_dev->entry)\n  pkt_dev->entry = proc_create_data(...)\n  if_unlock(t)\n\nThe kthread can pass the stale proc_dir_entry to proc_remove() after the\nrename path has freed it. A reproducer with a widened race window reports:\n\n  BUG: KASAN: slab-use-after-free in proc_remove+0x78/0x80\n  Read of size 8 at addr ffff8881478fea70 by task kpktgend_0/67\n  Call Trace:\n   proc_remove+0x78/0x80\n   pktgen_remove_device.isra.0+0x11c/0x4c0\n   pktgen_thread_worker+0x1214/0x6bc0\n   kthread+0x2c6/0x3b0\n  Allocated by task 95:\n   __proc_create+0x204/0x790\n   proc_create_data+0x72/0xe0\n   pktgen_thread_write+0xd61/0x1510\n  Freed by task 28:\n   kmem_cache_free+0xcb/0x3d0\n   proc_free_inode+0x5b/0x80\n   rcu_core+0x50a/0x1850\n  The buggy address belongs to the object at ffff8881478fea00\n   which belongs to the cache proc_dir_entry of size 192\n\nMove proc_remove() into the if_lock-protected list removal helper. Keep it\nbefore list_del_rcu() to preserve the ordering required by add_device().\nThe rename path must then finish replacing the entry before removal, or\nit observes that the device is no longer on the list."
    }
  ],
  "lastModified": "2026-08-23T13:16:44.380",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}