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GHSA-7Q8M-JHFW-FRRF

Vulnerability from github – Published: 2026-08-12 00:31 – Updated: 2026-08-12 00:31

Details

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

drm/amd/display: use kvzalloc to allocate struct dc

struct dc has grown large over time (most of it the two inlined dc_scratch_space copies) and now sits close to the page allocator's 4 MiB contiguous allocation limit. Its actual size is not fixed by the source alone, it also depends on the compiler and the .config, so it can easily cross 4 MiB, e.g. with a newer GCC or a config change.

dc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the request is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER, so the page allocator warns and returns NULL. dc_create() then fails, DM init fails and amdgpu probe aborts with -EINVAL:

WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380 dc_create+0x38/0x660 [amdgpu] amdgpu_dm_init+0x2d9/0x510 [amdgpu] dm_hw_init+0x1b/0x90 [amdgpu] amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu] amdgpu_driver_load_kms+0x19/0x80 [amdgpu] amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu]

dc_create() then returns NULL and DM init fails, which aborts the whole GPU init and makes amdgpu probe fail with -EINVAL ("hw_init of IP block failed -22"), leaving the display unusable. The subsequent amdgpu_irq_put() warnings during teardown are just fallout of unwinding a half-initialized device.

struct dc is a software-only bookkeeping structure that is never handed to hardware DMA and is only ever kept as an opaque pointer, so it does not require physically contiguous memory. Allocate it with kvzalloc() (and free it with kvfree()) so that the allocator can fall back to vmalloc() when a contiguous allocation of that size is not available, which also avoids the MAX_PAGE_ORDER warning entirely.

v2: - Rebase to amd-staging-drm-next.

(cherry picked from commit 991e0516a8072f2292681c6ae98a924ab0e32575)

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{
  "affected": [],
  "aliases": [
    "CVE-2026-68436"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-12T00:17:43Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: use kvzalloc to allocate struct dc\n\nstruct dc has grown large over time (most of it the two inlined\ndc_scratch_space copies) and now sits close to the page allocator\u0027s 4 MiB\ncontiguous allocation limit. Its actual size is not fixed by the source\nalone, it also depends on the compiler and the .config, so it can easily\ncross 4 MiB, e.g. with a newer GCC or a config change.\n\ndc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the\nrequest is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER,\nso the page allocator warns and returns NULL. dc_create() then fails, DM\ninit fails and amdgpu probe aborts with -EINVAL:\n\n  WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380\n   dc_create+0x38/0x660 [amdgpu]\n   amdgpu_dm_init+0x2d9/0x510 [amdgpu]\n   dm_hw_init+0x1b/0x90 [amdgpu]\n   amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu]\n   amdgpu_driver_load_kms+0x19/0x80 [amdgpu]\n   amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu]\n\ndc_create() then returns NULL and DM init fails, which aborts the whole\nGPU init and makes amdgpu probe fail with -EINVAL (\"hw_init of IP block\n\u003cdm\u003e failed -22\"), leaving the display unusable. The subsequent\namdgpu_irq_put() warnings during teardown are just fallout of unwinding\na half-initialized device.\n\nstruct dc is a software-only bookkeeping structure that is never handed\nto hardware DMA and is only ever kept as an opaque pointer, so it does\nnot require physically contiguous memory. Allocate it with kvzalloc()\n(and free it with kvfree()) so that the allocator can fall back to\nvmalloc() when a contiguous allocation of that size is not available,\nwhich also avoids the MAX_PAGE_ORDER warning entirely.\n\nv2:\n - Rebase to amd-staging-drm-next.\n\n(cherry picked from commit 991e0516a8072f2292681c6ae98a924ab0e32575)",
  "id": "GHSA-7q8m-jhfw-frrf",
  "modified": "2026-08-12T00:31:12Z",
  "published": "2026-08-12T00:31:12Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68436"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/75050390151a14802be433c3856ddcb483cecd24"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dbad70d40cad9c5e7586953275287fe7531fb811"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-68436 (GCVE-0-2026-68436)

Vulnerability from cvelistv5 – Published: 2026-08-12 00:07 – Updated: 2026-08-18 06:56

Title

drm/amd/display: use kvzalloc to allocate struct dc

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: use kvzalloc to allocate struct dc struct dc has grown large over time (most of it the two inlined dc_scratch_space copies) and now sits close to the page allocator's 4 MiB contiguous allocation limit. Its actual size is not fixed by the source alone, it also depends on the compiler and the .config, so it can easily cross 4 MiB, e.g. with a newer GCC or a config change. dc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the request is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER, so the page allocator warns and returns NULL. dc_create() then fails, DM init fails and amdgpu probe aborts with -EINVAL: WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380 dc_create+0x38/0x660 [amdgpu] amdgpu_dm_init+0x2d9/0x510 [amdgpu] dm_hw_init+0x1b/0x90 [amdgpu] amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu] amdgpu_driver_load_kms+0x19/0x80 [amdgpu] amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu] dc_create() then returns NULL and DM init fails, which aborts the whole GPU init and makes amdgpu probe fail with -EINVAL ("hw_init of IP block <dm> failed -22"), leaving the display unusable. The subsequent amdgpu_irq_put() warnings during teardown are just fallout of unwinding a half-initialized device. struct dc is a software-only bookkeeping structure that is never handed to hardware DMA and is only ever kept as an opaque pointer, so it does not require physically contiguous memory. Allocate it with kvzalloc() (and free it with kvfree()) so that the allocator can fall back to vmalloc() when a contiguous allocation of that size is not available, which also avoids the MAX_PAGE_ORDER warning entirely. v2: - Rebase to amd-staging-drm-next. (cherry picked from commit 991e0516a8072f2292681c6ae98a924ab0e32575)

Severity

No CVSS data available.

Assigner

Linux mitre root

References

2 references

URL	Tags
https://git.kernel.org/stable/c/dbad70d40cad9c5e7…
https://git.kernel.org/stable/c/75050390151a14802…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: d62d5551dd615f9e488b13595d69b308cd019e16 , < dbad70d40cad9c5e7586953275287fe7531fb811 (git) Affected: d62d5551dd615f9e488b13595d69b308cd019e16 , < 75050390151a14802be433c3856ddcb483cecd24 (git)
Linux	Linux	Affected: 6.10 Unaffected: 0 , < 6.10 (semver) Unaffected: 7.1.6 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/amd/display/dc/core/dc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "dbad70d40cad9c5e7586953275287fe7531fb811",
              "status": "affected",
              "version": "d62d5551dd615f9e488b13595d69b308cd019e16",
              "versionType": "git"
            },
            {
              "lessThan": "75050390151a14802be433c3856ddcb483cecd24",
              "status": "affected",
              "version": "d62d5551dd615f9e488b13595d69b308cd019e16",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/amd/display/dc/core/dc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: use kvzalloc to allocate struct dc\n\nstruct dc has grown large over time (most of it the two inlined\ndc_scratch_space copies) and now sits close to the page allocator\u0027s 4 MiB\ncontiguous allocation limit. Its actual size is not fixed by the source\nalone, it also depends on the compiler and the .config, so it can easily\ncross 4 MiB, e.g. with a newer GCC or a config change.\n\ndc_create() allocates it with kzalloc(). Once struct dc exceeds 4 MiB the\nrequest is rounded up to order 11 (8 MiB), which is above MAX_PAGE_ORDER,\nso the page allocator warns and returns NULL. dc_create() then fails, DM\ninit fails and amdgpu probe aborts with -EINVAL:\n\n  WARNING: mm/page_alloc.c:5197 at __alloc_frozen_pages_noprof+0x2f9/0x380\n   dc_create+0x38/0x660 [amdgpu]\n   amdgpu_dm_init+0x2d9/0x510 [amdgpu]\n   dm_hw_init+0x1b/0x90 [amdgpu]\n   amdgpu_device_init.cold+0x150d/0x1e13 [amdgpu]\n   amdgpu_driver_load_kms+0x19/0x80 [amdgpu]\n   amdgpu_pci_probe+0x1e2/0x4c0 [amdgpu]\n\ndc_create() then returns NULL and DM init fails, which aborts the whole\nGPU init and makes amdgpu probe fail with -EINVAL (\"hw_init of IP block\n\u003cdm\u003e failed -22\"), leaving the display unusable. The subsequent\namdgpu_irq_put() warnings during teardown are just fallout of unwinding\na half-initialized device.\n\nstruct dc is a software-only bookkeeping structure that is never handed\nto hardware DMA and is only ever kept as an opaque pointer, so it does\nnot require physically contiguous memory. Allocate it with kvzalloc()\n(and free it with kvfree()) so that the allocator can fall back to\nvmalloc() when a contiguous allocation of that size is not available,\nwhich also avoids the MAX_PAGE_ORDER warning entirely.\n\nv2:\n - Rebase to amd-staging-drm-next.\n\n(cherry picked from commit 991e0516a8072f2292681c6ae98a924ab0e32575)"
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-18T06:56:03.101Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/dbad70d40cad9c5e7586953275287fe7531fb811"
        },
        {
          "url": "https://git.kernel.org/stable/c/75050390151a14802be433c3856ddcb483cecd24"
        }
      ],
      "title": "drm/amd/display: use kvzalloc to allocate struct dc",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68436",
    "datePublished": "2026-08-12T00:07:24.698Z",
    "dateReserved": "2026-07-30T09:28:09.394Z",
    "dateUpdated": "2026-08-18T06:56:03.101Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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GHSA-7Q8M-JHFW-FRRF

CVE-2026-68436 (GCVE-0-2026-68436)

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