CVE-2026-64424

Estado: AnalizadaAlta (7.8)—

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

netpoll: fix a use-after-free on shutdown path

The problem happens when there is a pending TX worker running in parallel with the cleanup path.

This is what happens on netpoll shutdown path:

Because 3.1) doesn't really cancel the work, as the comment says "we can't call cancel_delayed_work_sync here, as we are in softirq", the TX worker can run after 4).

Tl;DR: queue_process() is not an RCU reader, it reaches npinfo through the work item via container_of().

Use disable_delayed_work_sync() to ensure the worker is completely stopped and prevent any future re-arming attempts. Once npinfo is set to NULL, senders will bail out and not queue new work.

Leer descripción completaMostrar menos

The disable flag ensures any in-flight re-arming attempts also fail silently.

In the future, we can do the cleanup inline here without needing the npinfo->rcu rcu_head, but that is net-next material.

Detalles técnicos trazas, registros y código del informe original

There is a use-after-free error on netpoll, which is clearly detected by
KASAN.

      BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80
      Read of size 1 at addr ... by task kworker/9:1
      Workqueue: events queue_process
      Call Trace:
       skb_dequeue+0x1e/0xb0
       queue_process+0x2c/0x600
       process_scheduled_works+0x4b6/0x850
       worker_thread+0x414/0x5a0
      Allocated by task 242:
       __netpoll_setup+0x201/0x4a0
       netpoll_setup+0x249/0x550
       enabled_store+0x32f/0x380
      Freed by task 0:
       kfree+0x1b7/0x540
       rcu_core+0x3f8/0x7a0

1) __netpoll_cleanup() is called
2) set dev->npinfo to NULL
3) call_rcu() with rcu_cleanup_netpoll_info()
  3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with
       cancel_delayed_work(), but doesn't wait for the worker to finish
4) and kfree(npinfo);

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: 0.17%
Percentil entre todas las CVEs puntuadas: 6
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 escalation75 %
Impacto principalT1059 Command and Scripting Interpreterexecution65 %
Impacto secundarioT1499.004 Application or System Exploitationimpact55 %

CVE-2026-64424 es una use-after-free (CWE-416) en kernel Linux con AV:L/PR:L/UI:N, escalada local; permite ejecución de código e inanición de recursos en worker kworker.

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

Execution Prevention Threat Intelligence Program Restrict Web-Based Content Privileged Account Management Limit Software Installation Filter Network Traffic

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-416

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-64424",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "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": "38e6bc185d9544dfad1774b3f8902a0b061aea25",
              "lessThan": "95ecc5b58042f6b6743b589e6588f1cd7ba336aa",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "38e6bc185d9544dfad1774b3f8902a0b061aea25",
              "lessThan": "a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "38e6bc185d9544dfad1774b3f8902a0b061aea25",
              "lessThan": "5ed09a108d93a3b002cc79823d9455b50c4a8be7",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "38e6bc185d9544dfad1774b3f8902a0b061aea25",
              "lessThan": "45f1458a85017a023f138b22ac5c76abd477db42",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "net/core/netpoll.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.6"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "3.6",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/core/netpoll.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-07-25T10:17:26.483",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/45f1458a85017a023f138b22ac5c76abd477db42",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5ed09a108d93a3b002cc79823d9455b50c4a8be7",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/95ecc5b58042f6b6743b589e6588f1cd7ba336aa",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetpoll: fix a use-after-free on shutdown path\n\nThere is a use-after-free error on netpoll, which is clearly detected by\nKASAN.\n\n      BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80\n      Read of size 1 at addr ... by task kworker/9:1\n      Workqueue: events queue_process\n      Call Trace:\n       skb_dequeue+0x1e/0xb0\n       queue_process+0x2c/0x600\n       process_scheduled_works+0x4b6/0x850\n       worker_thread+0x414/0x5a0\n      Allocated by task 242:\n       __netpoll_setup+0x201/0x4a0\n       netpoll_setup+0x249/0x550\n       enabled_store+0x32f/0x380\n      Freed by task 0:\n       kfree+0x1b7/0x540\n       rcu_core+0x3f8/0x7a0\n\nThe problem happens when there is a pending TX worker running in\nparallel with the cleanup path.\n\nThis is what happens on netpoll shutdown path:\n\n1) __netpoll_cleanup() is called\n2) set dev->npinfo to NULL\n3) call_rcu() with rcu_cleanup_netpoll_info()\n  3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with\n       cancel_delayed_work(), but doesn't wait for the worker to finish\n4) and kfree(npinfo);\n\nBecause 3.1) doesn't really cancel the work, as the comment says \"we\ncan't call cancel_delayed_work_sync here, as we are in softirq\", the TX\nworker can run after 4).\n\nTl;DR: queue_process() is not an RCU reader, it reaches npinfo through\nthe work item via container_of().\n\nUse disable_delayed_work_sync() to ensure the worker is completely\nstopped and prevent any future re-arming attempts. Once npinfo is set\nto NULL, senders will bail out and not queue new work. The disable flag\nensures any in-flight re-arming attempts also fail silently.\n\nIn the future, we can do the cleanup inline here without needing the\nnpinfo->rcu rcu_head, but that is net-next material."
    }
  ],
  "lastModified": "2026-09-04T15:53:06.260",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "CAD8F820-D747-4A98-94FA-9C4333E80C3A",
              "versionEndExcluding": "6.12.96",
              "versionStartIncluding": "3.6.1"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "914AE4BC-3D59-4C5A-9DB5-9CE327B429F7",
              "versionEndExcluding": "6.18.39",
              "versionStartIncluding": "6.13"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42",
              "versionEndExcluding": "7.1.4",
              "versionStartIncluding": "6.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:3.6:-:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E7D72FF4-3906-4585-B39A-A9B194F53204"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:3.6:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E0FCBD80-8462-4642-B2F0-54896776CF07"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:3.6:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "42F72762-D825-4B81-93BB-5B7F54313F46"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:3.6:rc5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "41FDE042-F389-4580-BEBB-EBAB4F562477"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:3.6:rc6:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "329C7DD0-9CEA-4D15-B0FE-B3565EE53A63"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:3.6:rc7:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A6067C5D-29B3-4EE2-BDCA-3F204F25F1C0"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "5E8B9085-7ADB-4A05-89EF-12949B6A0509"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}