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CVE-2026-89803

Estado: RecibidaAlta (7.8)—

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

drm/nouveau: unsubscribe the channel-kill event before the fence context

nouveau_channel_del() tears the fence context down first and only drops the channel-kill subscription later, in the middle of the nvif object teardown:

The subscribed handler is nouveau_channel_killed(), which calls nouveau_channel_kill() and from there nouveau_fence_context_kill() on chan->fence. A kill event delivered in that window takes fctx->lock and walks fctx->pending on a fence context that context_del() has already freed.

Nothing reaches this below Fermi today, because the subscription is gated on FERMI_CHANNEL_GPFIFO and nothing kills a channel there.

Leer descripción completaMostrar menos

On Fermi and newer the window is real but narrow, since a kill has to land exactly while the channel is being destroyed. That is reason enough on its own, which is why this carries a Fixes: tag. The last patch in this series subscribes Tesla channels as well; nothing kills those today, so it does not widen the exposure now, but it is the groundwork for a recovery path that would, and the ordering is better fixed before that lands than alongside it.

Drop the subscription before anything it depends on is torn down.

Detalles técnicos trazas, registros y código del informe original
	if (chan->fence)
		nouveau_fence(chan->cli->drm)->context_del(chan);
	...
	nvif_object_dtor(&chan->vram);
	nvif_event_dtor(&chan->kill);

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 local (AV:L, PR:L) en kernel Linux que causa race condition en destrucción de contexto de fence. Permite escalada (T1068) y negación de servicio (crash/DoS) por acceso a memoria liberada en ventana de sincronización.

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)

Mostrar
{
  "id": "CVE-2026-89803",
  "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": "ea13e5abf807ea912ce84eef6a1946b9a38c6508",
              "lessThan": "f5a79a9ebfbafb87ca7a896e8d6b5f33a98d097e",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ea13e5abf807ea912ce84eef6a1946b9a38c6508",
              "lessThan": "f3830fdd6930e233d727f29eee1617f7e6a0e9e5",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ea13e5abf807ea912ce84eef6a1946b9a38c6508",
              "lessThan": "1fef7553dc628295c1208a4f2ac2094c62886e5d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ea13e5abf807ea912ce84eef6a1946b9a38c6508",
              "lessThan": "511585987d27d8cb668acebd399fc4deda23404c",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/gpu/drm/nouveau/nouveau_chan.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.6"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.6",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.51",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.5",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/gpu/drm/nouveau/nouveau_chan.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-16T11:16:45.227",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1fef7553dc628295c1208a4f2ac2094c62886e5d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/511585987d27d8cb668acebd399fc4deda23404c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f3830fdd6930e233d727f29eee1617f7e6a0e9e5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f5a79a9ebfbafb87ca7a896e8d6b5f33a98d097e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/nouveau: unsubscribe the channel-kill event before the fence context\n\nnouveau_channel_del() tears the fence context down first and only drops\nthe channel-kill subscription later, in the middle of the nvif object\nteardown:\n\n\tif (chan->fence)\n\t\tnouveau_fence(chan->cli->drm)->context_del(chan);\n\t...\n\tnvif_object_dtor(&chan->vram);\n\tnvif_event_dtor(&chan->kill);\n\nThe subscribed handler is nouveau_channel_killed(), which calls\nnouveau_channel_kill() and from there nouveau_fence_context_kill() on\nchan->fence. A kill event delivered in that window takes fctx->lock and\nwalks fctx->pending on a fence context that context_del() has already\nfreed.\n\nNothing reaches this below Fermi today, because the subscription is\ngated on FERMI_CHANNEL_GPFIFO and nothing kills a channel there. On\nFermi and newer the window is real but narrow, since a kill has to land\nexactly while the channel is being destroyed. That is reason enough on\nits own, which is why this carries a Fixes: tag. The last patch in this\nseries subscribes Tesla channels as well; nothing kills those today, so\nit does not widen the exposure now, but it is the groundwork for a\nrecovery path that would, and the ordering is better fixed before that\nlands than alongside it.\n\nDrop the subscription before anything it depends on is torn down."
    }
  ],
  "lastModified": "2026-09-16T15:18:09.993",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}