CVE-2026-72342

Estado: RecibidaAlta (8.4)—

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

net/mlx5e: Fix HV VHCA stats agent registration race

mlx5e_hv_vhca_stats_create() registers the stats agent through mlx5_hv_vhca_agent_create(). The helper publishes the agent in hv_vhca->agents[type] under agents_lock and immediately schedules an asynchronous control invalidation on the HV VHCA workqueue before returning to mlx5e.

The asynchronous invalidation invokes the control agent's invalidate callback, which reads the hypervisor control block and forwards the command to mlx5e_hv_vhca_stats_control(). That callback may either:

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However, the delayed_work and priv->stats_agent.agent are only initialized after mlx5_hv_vhca_agent_create() returns to mlx5e:

If the asynchronous control path runs before the two assignments above, it can:

Fix this by:

While at it, access priv->stats_agent.agent with READ_ONCE()/WRITE_ONCE() for the cross-CPU access with the worker, and clear priv->stats_agent.buf on the agent_create() failure path.

Detalles técnicos trazas, registros y código del informe original

  - call cancel_delayed_work_sync(&priv->stats_agent.work), or
  - call queue_delayed_work(priv->wq, &sagent->work, sagent->delay).

    agent = mlx5_hv_vhca_agent_create(...);   /* publish + invalidate */
    ...
    priv->stats_agent.agent = agent;          /* too late */
    INIT_DELAYED_WORK(&priv->stats_agent.work, ...); /* too late */

  - Operate on an uninitialized delayed_work whose timer.function is
    NULL. queue_delayed_work() calls add_timer() unconditionally, so
    when the timer expires the timer softirq invokes a NULL function
    pointer.
  - Re-initialize the timer later through INIT_DELAYED_WORK() while
    the timer is already enqueued in the timer wheel, corrupting the
    hlist (entry.pprev cleared while the previous bucket node still
    points at this entry).
  - When the worker eventually runs, mlx5e_hv_vhca_stats_work() reads
    sagent->agent (NULL) and dereferences it inside
    mlx5_hv_vhca_agent_write().

  - Initializing priv->stats_agent.work before invoking
    mlx5_hv_vhca_agent_create(), so the work is always in a valid
    state when the control callback observes it.
  - Adding a struct mlx5_hv_vhca_agent **ctx_update out-parameter
    to mlx5_hv_vhca_agent_create(). The helper writes the agent
    pointer to *ctx_update before publishing into hv_vhca->agents[]
    and triggering the agents_update flow, so any callback
    subsequently invoked from that flow already sees a valid
    priv->stats_agent.agent. This avoids having the control
    callback participate in agent initialization.

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 8.4

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.20%
Percentil entre todas las CVEs puntuadas: 8
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 %

AV:L sin interacción del usuario permite escalada local. La corrupción de hlist y NULL pointer dereference pueden causar DoS o ejecución de código con privilegios elevados.

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)

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{
  "id": "CVE-2026-72342",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.4,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.5
      }
    ]
  },
  "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": "cef35af34d6dc3792333075115c7deb7062b6e18",
              "lessThan": "b0fd6d3bb06182f19f3b59a53f57b5098b99048a",
              "versionType": "git"
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            {
              "status": "affected",
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              "versionType": "git"
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              "version": "cef35af34d6dc3792333075115c7deb7062b6e18",
              "lessThan": "e8fc3304cb67fb1d7d11ff9ef9abd5fb64e7e1d5",
              "versionType": "git"
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            {
              "status": "affected",
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              "versionType": "git"
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            {
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            {
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              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c",
            "drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.c",
            "drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.h"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.4"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.4",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver",
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            },
            {
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c",
            "drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.c",
            "drivers/net/ethernet/mellanox/mlx5/core/lib/hv_vhca.h"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T06:22:07.520",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/24c77044cdfcf5b8b2e9f3b620d8b9aa392d9add",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/60fddda7207d81fea71463abd403f0b10f74f2e1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/89b25b5f46f488ea3b29b3444864c76944c9075b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b0fd6d3bb06182f19f3b59a53f57b5098b99048a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e8fc3304cb67fb1d7d11ff9ef9abd5fb64e7e1d5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f5677797b094c3ec5fb350eb8ea7710b88a3d018",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix HV VHCA stats agent registration race\n\nmlx5e_hv_vhca_stats_create() registers the stats agent through\nmlx5_hv_vhca_agent_create(). The helper publishes the agent in\nhv_vhca->agents[type] under agents_lock and immediately schedules an\nasynchronous control invalidation on the HV VHCA workqueue before\nreturning to mlx5e.\n\nThe asynchronous invalidation invokes the control agent's invalidate\ncallback, which reads the hypervisor control block and forwards the\ncommand to mlx5e_hv_vhca_stats_control(). That callback may either:\n\n  - call cancel_delayed_work_sync(&priv->stats_agent.work), or\n  - call queue_delayed_work(priv->wq, &sagent->work, sagent->delay).\n\nHowever, the delayed_work and priv->stats_agent.agent are only\ninitialized after mlx5_hv_vhca_agent_create() returns to mlx5e:\n\n    agent = mlx5_hv_vhca_agent_create(...);   /* publish + invalidate */\n    ...\n    priv->stats_agent.agent = agent;          /* too late */\n    INIT_DELAYED_WORK(&priv->stats_agent.work, ...); /* too late */\n\nIf the asynchronous control path runs before the two assignments\nabove, it can:\n\n  - Operate on an uninitialized delayed_work whose timer.function is\n    NULL. queue_delayed_work() calls add_timer() unconditionally, so\n    when the timer expires the timer softirq invokes a NULL function\n    pointer.\n  - Re-initialize the timer later through INIT_DELAYED_WORK() while\n    the timer is already enqueued in the timer wheel, corrupting the\n    hlist (entry.pprev cleared while the previous bucket node still\n    points at this entry).\n  - When the worker eventually runs, mlx5e_hv_vhca_stats_work() reads\n    sagent->agent (NULL) and dereferences it inside\n    mlx5_hv_vhca_agent_write().\n\nFix this by:\n\n  - Initializing priv->stats_agent.work before invoking\n    mlx5_hv_vhca_agent_create(), so the work is always in a valid\n    state when the control callback observes it.\n  - Adding a struct mlx5_hv_vhca_agent **ctx_update out-parameter\n    to mlx5_hv_vhca_agent_create(). The helper writes the agent\n    pointer to *ctx_update before publishing into hv_vhca->agents[]\n    and triggering the agents_update flow, so any callback\n    subsequently invoked from that flow already sees a valid\n    priv->stats_agent.agent. This avoids having the control\n    callback participate in agent initialization.\n\nWhile at it, access priv->stats_agent.agent with\nREAD_ONCE()/WRITE_ONCE() for the cross-CPU access with the worker, and\nclear priv->stats_agent.buf on the agent_create() failure path."
    }
  ],
  "lastModified": "2026-08-17T06:18:38.010",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}