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CVE-2026-68384

Estado: RecibidaAlta (7.8)—

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

drm/xe/vf: Fix VF CCS attach/detach race with in-flight BO moves

xe_bo_move() attaches VF CCS read/write batch buffers (BBs) to a BO after it transitions NULL/SYSTEM -> TT, and detaches them after it transitions TT -> SYSTEM. Both operations were done synchronously on the CPU immediately after building the move's copy/clear fence, without waiting for that fence to signal. This creates two races with VF migration:

Fix both races:

While here, also fix xe_sriov_vf_ccs_attach_bo() to properly unwind and propagate errors: the per-context loop previously never broke out on error, silently discarding earlier failures.

Leer descripción completaMostrar menos

Unwind by clearing each attached context directly via xe_migrate_ccs_rw_copy_clear() instead of reusing xe_sriov_vf_ccs_detach_bo(), which requires both contexts to be attached before it will clean up either one.

(cherry picked from commit d45ad0aa7a1eb5d7288b5ed948b05695611dc39e)

Detalles técnicos trazas, registros y código del informe original
- Attach happens too late relative to the copy job it is meant to
  protect. If the copy job is submitted before the CCS BBs are
  attached, a VF migration event that pauses execution mid-copy can
  observe partially copied CCS metadata without the attach state
  needed to correctly save/restore it.

- Detach happens too early relative to the copy job that moves data
  out of TT. The CCS BBs are torn down right after the copy fence is
  obtained, while the actual blit may still be in flight. A VF
  migration event that pauses execution mid-copy can then race the
  save/restore path against the still-running blit, and the CCS BBs
  it would need to make sense of the paused state have already been
  removed.

- Move the attach call to before the copy/clear job is submitted, so
  the CCS BBs are already registered by the time the copy runs. On
  attach failure, unwind and bail out of the move. xe_migrate_ccs_rw_copy()
  now takes the destination resource explicitly, since bo->ttm.resource
  is not updated to the new resource until after the move commits.

- Detach only after explicitly waiting for the copy fence to signal,
  instead of tearing down the CCS BBs immediately after obtaining it.

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 que causa race condition en manejo de memoria durante migración de máquinas virtuales. Permite DoS por corrupción de datos o pausa del sistema explotando sincronización defectuosa.

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 ProgramRestrict File and Directory PermissionsRemote Data StorageFilter Network TrafficExecution PreventionEncrypt Sensitive Information

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-2026-68384",
  "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": "864690cf4dd62482b6dd049d82c509886c904303",
              "lessThan": "35ba43b541117bfb595e4b807ba447cf4335cc7d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "864690cf4dd62482b6dd049d82c509886c904303",
              "lessThan": "f2ebfd5cc87f1393a30c8b8b0a6c20cb22cffa97",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "864690cf4dd62482b6dd049d82c509886c904303",
              "lessThan": "56441f9e08ad68697295b8835266d2bc48ab59b5",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/gpu/drm/xe/xe_bo.c",
            "drivers/gpu/drm/xe/xe_migrate.c",
            "drivers/gpu/drm/xe/xe_migrate.h",
            "drivers/gpu/drm/xe/xe_sriov_vf_ccs.c",
            "drivers/gpu/drm/xe/xe_sriov_vf_ccs.h"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.18"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.18",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/gpu/drm/xe/xe_bo.c",
            "drivers/gpu/drm/xe/xe_migrate.c",
            "drivers/gpu/drm/xe/xe_migrate.h",
            "drivers/gpu/drm/xe/xe_sriov_vf_ccs.c",
            "drivers/gpu/drm/xe/xe_sriov_vf_ccs.h"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-10T13:20:31.593",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/35ba43b541117bfb595e4b807ba447cf4335cc7d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/56441f9e08ad68697295b8835266d2bc48ab59b5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f2ebfd5cc87f1393a30c8b8b0a6c20cb22cffa97",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe/vf: Fix VF CCS attach/detach race with in-flight BO moves\n\nxe_bo_move() attaches VF CCS read/write batch buffers (BBs) to a BO\nafter it transitions NULL/SYSTEM -> TT, and detaches them after it\ntransitions TT -> SYSTEM. Both operations were done synchronously on\nthe CPU immediately after building the move's copy/clear fence,\nwithout waiting for that fence to signal. This creates two races with\nVF migration:\n\n- Attach happens too late relative to the copy job it is meant to\n  protect. If the copy job is submitted before the CCS BBs are\n  attached, a VF migration event that pauses execution mid-copy can\n  observe partially copied CCS metadata without the attach state\n  needed to correctly save/restore it.\n\n- Detach happens too early relative to the copy job that moves data\n  out of TT. The CCS BBs are torn down right after the copy fence is\n  obtained, while the actual blit may still be in flight. A VF\n  migration event that pauses execution mid-copy can then race the\n  save/restore path against the still-running blit, and the CCS BBs\n  it would need to make sense of the paused state have already been\n  removed.\n\nFix both races:\n\n- Move the attach call to before the copy/clear job is submitted, so\n  the CCS BBs are already registered by the time the copy runs. On\n  attach failure, unwind and bail out of the move. xe_migrate_ccs_rw_copy()\n  now takes the destination resource explicitly, since bo->ttm.resource\n  is not updated to the new resource until after the move commits.\n\n- Detach only after explicitly waiting for the copy fence to signal,\n  instead of tearing down the CCS BBs immediately after obtaining it.\n\nWhile here, also fix xe_sriov_vf_ccs_attach_bo() to properly unwind and\npropagate errors: the per-context loop previously never broke out on\nerror, silently discarding earlier failures. Unwind by clearing each\nattached context directly via xe_migrate_ccs_rw_copy_clear() instead of\nreusing xe_sriov_vf_ccs_detach_bo(), which requires both contexts to be\nattached before it will clean up either one.\n\n(cherry picked from commit d45ad0aa7a1eb5d7288b5ed948b05695611dc39e)"
    }
  ],
  "lastModified": "2026-08-17T06:17:46.920",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}