CVE-2026-63863 (GCVE-0-2026-63863)
Vulnerability from cvelistv5
Published
2026-07-19 14:04
Modified
2026-08-05 12:36
Severity ?
8.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm() There is a unbalanced lock/unlock to gpusvm notifier lock: [ 931.045868] ===================================== [ 931.046509] WARNING: bad unlock balance detected! [ 931.047149] 6.19.0-rc6+xe-**************** #9 Tainted: G U [ 931.048150] ------------------------------------- [ 931.048790] kworker/u5:0/51 is trying to release lock (&gpusvm->notifier_lock) at: [ 931.049801] [<ffffffffa090c0d8>] drm_gpusvm_scan_mm+0x188/0x460 [drm_gpusvm_helper] [ 931.050802] but there are no more locks to release! [ 931.051463] The drm_gpusvm_notifier_unlock() sits under err_free label and the first jump to err_free is just before calling the drm_gpusvm_notifier_lock() causing unbalanced unlock.
References
Impacted products
Vendor Product Version
Linux Linux Version: f1d08a5864822684773105c60528e2abb577ca6c
Version: f1d08a5864822684773105c60528e2abb577ca6c
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/drm_gpusvm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "8efaa47a871662a8c21b819cec60786f7ef17ab4",
              "status": "affected",
              "version": "f1d08a5864822684773105c60528e2abb577ca6c",
              "versionType": "git"
            },
            {
              "lessThan": "d287dee565c3c32e1ed76ec1847af46809c29b90",
              "status": "affected",
              "version": "f1d08a5864822684773105c60528e2abb577ca6c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/drm_gpusvm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "lessThan": "7.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.10",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "7.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm()\n\nThere is a unbalanced lock/unlock to gpusvm notifier lock:\n[  931.045868] =====================================\n[  931.046509] WARNING: bad unlock balance detected!\n[  931.047149] 6.19.0-rc6+xe-**************** #9 Tainted: G     U\n[  931.048150] -------------------------------------\n[  931.048790] kworker/u5:0/51 is trying to release lock (\u0026gpusvm-\u003enotifier_lock) at:\n[  931.049801] [\u003cffffffffa090c0d8\u003e] drm_gpusvm_scan_mm+0x188/0x460 [drm_gpusvm_helper]\n[  931.050802] but there are no more locks to release!\n[  931.051463]\n\nThe drm_gpusvm_notifier_unlock() sits under err_free label and the\nfirst jump to err_free is just before calling the\ndrm_gpusvm_notifier_lock() causing unbalanced unlock."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerable code is only reached via Intel Xe DRM ioctls (DRM_XE_VM_BIND prefetch, GPU page-fault handling) on /dev/dri/renderD*, which require local access to the GPU device node.\nAC:L - An attacker can reliably trigger the bug by racing CPU memory operations (munmap/mremap/mprotect) against GPU SVM VRAM migration to force hmm_range_fault() to return an error or time out on -EBUSY, hitting the err_free path without holding notifier_lock.\nPR:L - Exploitation requires opening the DRM render node (DRM_RENDER_ALLOW), which is available to unprivileged users in the render group on typical desktop and cloud GPU instances, not root or capabilities.\nUI:N - No victim interaction is required; the attacker triggers the condition through their own GPU VM bindings, compute submissions, and concurrent memory manipulation.\nS:C - Corrupting notifier_lock breaks the documented IOMMU security model for GPU SVM, allowing GPU DMA operations to proceed without proper invalidation synchronization and potentially accessing host memory outside the attacker\u0027s GPU context.\nC:H - Rwsem corruption from the spurious unlock can desynchronize invalidation from migration, enabling races where the GPU reads stale or freed pages that may have been reallocated, constituting arbitrary memory disclosure.\nI:H - The same lock corruption can allow GPU DMA writes to pages during or after invalidation races, providing a path to arbitrary memory corruption and potential privilege escalation.\nA:H - The bug triggers a kernel lockdep warning (\"bad unlock balance detected\") and rwsem corruption can cause kernel oops, hangs, or panic during subsequent notifier_lock operations."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:36:39.194Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/8efaa47a871662a8c21b819cec60786f7ef17ab4"
        },
        {
          "url": "https://git.kernel.org/stable/c/d287dee565c3c32e1ed76ec1847af46809c29b90"
        }
      ],
      "title": "drm/gpusvm: Fix unbalanced unlock in drm_gpusvm_scan_mm()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-63863",
    "datePublished": "2026-07-19T14:04:49.967Z",
    "dateReserved": "2026-07-19T07:54:57.017Z",
    "dateUpdated": "2026-08-05T12:36:39.194Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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