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CVE-2026-98510

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: drm/xe/vm: nuke PTs only after unlinking contested VMAs In xe_vm_close_and_put(), external-BO VMAs are queued on the contested list for deferred destruction via xe_vma_destroy_unlocked(). However, xe_vm_pt_destroy() was previously invoked before processing contested VMAs, destroying vm->pt_root while those VMAs were still linked to their respective buffer objects (vm_bo->list.gpuva). If a concurrent thread evicts one of those shared buffer objects, xe_bo_trigger_rebind() holding only bo->resv walks the BO's VMAs and, in fault mode, calls xe_vm_invalidate_vma() -> xe_pt_zap_ptes(). Because vm->pt_root[tile->id] is already NULL, dereferencing pt->level causes a NULL ptr deref. Fix this by deferring xe_vm_free_scratch() and xe_vm_pt_destroy() until after all contested VMAs have been unlinked and destroyed. User is reporting hitting a NULL ptr deref in xe_pt_zap_ptes(), which could be explained by this race. (cherry picked from commit c2863648959489767f08892fd6e90577d2ea0b6a)

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-10-18 16:17:02.203000
Last modified
2026-10-24 14:16:45.137000
View original CVE JSON
{
  "id": "CVE-2026-98510",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:17:02.203",
  "lastModified": "2026-10-24T14:16:45.137",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe/vm: nuke PTs only after unlinking contested VMAs\n\nIn xe_vm_close_and_put(), external-BO VMAs are queued on the contested\nlist for deferred destruction via xe_vma_destroy_unlocked(). However,\nxe_vm_pt_destroy() was previously invoked before processing contested\nVMAs, destroying vm->pt_root while those VMAs were still linked to their\nrespective buffer objects (vm_bo->list.gpuva).\n\nIf a concurrent thread evicts one of those shared buffer objects,\nxe_bo_trigger_rebind() holding only bo->resv walks the BO's VMAs and, in\nfault mode, calls xe_vm_invalidate_vma() -> xe_pt_zap_ptes(). Because\nvm->pt_root[tile->id] is already NULL, dereferencing pt->level causes a\nNULL ptr deref.\n\nFix this by deferring xe_vm_free_scratch() and xe_vm_pt_destroy() until\nafter all contested VMAs have been unlinked and destroyed.\n\nUser is reporting hitting a NULL ptr deref in xe_pt_zap_ptes(), which\ncould be explained by this race.\n\n(cherry picked from commit c2863648959489767f08892fd6e90577d2ea0b6a)"
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/gpu/drm/xe/xe_vm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "b06d47be7c83165d3b3e45e1d5f9520b79c7f5cc",
              "lessThan": "70fddc065ac80845ffd33095b3635d59883cf7e6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "b06d47be7c83165d3b3e45e1d5f9520b79c7f5cc",
              "lessThan": "ba678c2b02e0d36b53deb5a6d5e5ea044d36def7",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "b06d47be7c83165d3b3e45e1d5f9520b79c7f5cc",
              "lessThan": "bddaa5e4094c134452c29e20a26c4718827e4cb1",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "b06d47be7c83165d3b3e45e1d5f9520b79c7f5cc",
              "lessThan": "24a22fb3c731474b68e986af6804db450fb88617",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/gpu/drm/xe/xe_vm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.8",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.8",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.112",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.55",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.9",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/24a22fb3c731474b68e986af6804db450fb88617",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/70fddc065ac80845ffd33095b3635d59883cf7e6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ba678c2b02e0d36b53deb5a6d5e5ea044d36def7",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/bddaa5e4094c134452c29e20a26c4718827e4cb1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}