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CVE-2026-74465

Estado: RecibidaAlta (7.8)—

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

net: openvswitch: fix potential UAF on meter attach failure

While attaching a newly created meter attach_meter() function makes the new meter visible to other CPUs but can still fail afterwards. On failure, it detaches the meter back and returns an error.

However, this is an unexpected behavior for the ovs_meter_cmd_set() that uses a plain kfree(meter) on attach failure without waiting for RCU readers to stop using it, assuming it was never visible.

This is never a problem for ovs-vswitchd as it always creates meters before creating any flows that use them. But the UAF can be triggered with a custom application using uAPI:

Leer descripción completaMostrar menos

Fix that by making sure attach_meter() doesn't make the meter visible until all the checks are done and the function can't fail anymore.

This also makes sure the "hash" value is calculated after the potential re-sizing of the table.

Reported by Trend Micro's Zero Day Initiative as ZDI-CAN-31642.

Detalles técnicos trazas, registros y código del informe original
 BUG: KASAN: slab-use-after-free in ovs_meter_execute (net/openvswitch/meter.c:653)
 Read of size 8 at addr ffff88810d152650 by task meter/2508

 Call Trace:
  ovs_meter_execute (net/openvswitch/meter.c:653)
  do_execute_actions (net/openvswitch/actions.c:1407)
  ovs_execute_actions (net/openvswitch/actions.c:1584)
  ovs_packet_cmd_execute (net/openvswitch/datapath.c:703)
  ...
  netlink_sendmsg (af_netlink.c:1900)

 Allocated by task 2519:
  __kasan_kmalloc (mm/kasan/common.c:398 mm/kasan/common.c:415)
  ovs_meter_cmd_set (net/openvswitch/meter.c:422)
  ...
  netlink_sendmsg (af_netlink.c:1900)

 Freed by task 2519:
  kfree (mm/slub.c:2705 mm/slub.c:6405 mm/slub.c:6720)
  ovs_meter_cmd_set (net/openvswitch/meter.c:479)
  ...
  netlink_sendmsg (af_netlink.c:1900)

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 de UAF en kernel Linux (AV:L, PR:L) que permite DoS por crash, típica de escalada local; sin acceso explícito a datos o ejecución de comandos.

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 ProgramFilter Network TrafficExecution PreventionApplication Isolation and SandboxingExploit ProtectionUpdate 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 KernelAI

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-74465",
  "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": "c7c4c44c9a95d87e50ced38f7480e779cb472174",
              "lessThan": "496f3013c6ff759249abcfb2da2361c1a3e2e66d",
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            {
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              "lessThan": "b0de3b58dac3b02b528f72ee0397728aed11f993",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "c7c4c44c9a95d87e50ced38f7480e779cb472174",
              "lessThan": "0310d1fa7f9debd0d89629e9f14c7975a47eaa9a",
              "versionType": "git"
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              "lessThan": "4d03e5fa3fbb1df15258a1eb3d6963f0d65659b3",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "c7c4c44c9a95d87e50ced38f7480e779cb472174",
              "lessThan": "90623c9499627803ef3f04fa25a3199402d4fb95",
              "versionType": "git"
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            {
              "status": "affected",
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          ],
          "programFiles": [
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          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.8"
            },
            {
              "status": "unaffected",
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              "lessThan": "5.8",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.151",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.44",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "net/openvswitch/meter.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T13:17:51.190",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0310d1fa7f9debd0d89629e9f14c7975a47eaa9a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/431a295d93f76fbdb6a7cfce92a9e3dfee1e5d61",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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      "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"
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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: openvswitch: fix potential UAF on meter attach failure\n\nWhile attaching a newly created meter attach_meter() function makes\nthe new meter visible to other CPUs but can still fail afterwards.\nOn failure, it detaches the meter back and returns an error.\n\nHowever, this is an unexpected behavior for the ovs_meter_cmd_set()\nthat uses a plain kfree(meter) on attach failure without waiting for\nRCU readers to stop using it, assuming it was never visible.\n\nThis is never a problem for ovs-vswitchd as it always creates meters\nbefore creating any flows that use them.  But the UAF can be triggered\nwith a custom application using uAPI:\n\n BUG: KASAN: slab-use-after-free in ovs_meter_execute (net/openvswitch/meter.c:653)\n Read of size 8 at addr ffff88810d152650 by task meter/2508\n\n Call Trace:\n  ovs_meter_execute (net/openvswitch/meter.c:653)\n  do_execute_actions (net/openvswitch/actions.c:1407)\n  ovs_execute_actions (net/openvswitch/actions.c:1584)\n  ovs_packet_cmd_execute (net/openvswitch/datapath.c:703)\n  ...\n  netlink_sendmsg (af_netlink.c:1900)\n\n Allocated by task 2519:\n  __kasan_kmalloc (mm/kasan/common.c:398 mm/kasan/common.c:415)\n  ovs_meter_cmd_set (net/openvswitch/meter.c:422)\n  ...\n  netlink_sendmsg (af_netlink.c:1900)\n\n Freed by task 2519:\n  kfree (mm/slub.c:2705 mm/slub.c:6405 mm/slub.c:6720)\n  ovs_meter_cmd_set (net/openvswitch/meter.c:479)\n  ...\n  netlink_sendmsg (af_netlink.c:1900)\n\nFix that by making sure attach_meter() doesn't make the meter visible\nuntil all the checks are done and the function can't fail anymore.\n\nThis also makes sure the \"hash\" value is calculated after the potential\nre-sizing of the table.\n\nReported by Trend Micro's Zero Day Initiative as ZDI-CAN-31642."
    }
  ],
  "lastModified": "2026-08-19T17:21:03.497",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}