CVE-2026-68107 (GCVE-0-2026-68107)
Vulnerability from cvelistv5
Published
2026-08-10 11:58
Modified
2026-08-17 04:58
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/amdgpu/vcn4: avoid rereading IB param length Reuse the parameter length returned by vcn_v4_0_enc_find_ib_param() instead of rereading it from the IB. This avoids a potential TOCTOU issue if the IB contents change between reads. (cherry picked from commit dbb02b4755f8c1f3773263f2d779872c1c0c073a)
References
Impacted products
Vendor Product Version
Linux Linux Version: cfdde9197ecd957281507be99af172671a57755c
Version: 6dc4eddeb7e6cca7e1ab32cafbda79d06e652d84
Version: 2b10cb58d7a3fd621ec9b2ba765a092e562ef998
Version: 2b10cb58d7a3fd621ec9b2ba765a092e562ef998
Version: 2b10cb58d7a3fd621ec9b2ba765a092e562ef998
Version: b1dc92f55b22a80ded8f0263c9ef4ba902303895
Version: 6.6.107   ≤
Version: 6.12.48   ≤
Version: 6.16.8   ≤
Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bbbe6a2a8d8dc87243438d3ffea2083b52d882d9",
              "status": "affected",
              "version": "cfdde9197ecd957281507be99af172671a57755c",
              "versionType": "git"
            },
            {
              "lessThan": "ff6aa542d91d76a185f69bd1997b94a560ff5f6b",
              "status": "affected",
              "version": "6dc4eddeb7e6cca7e1ab32cafbda79d06e652d84",
              "versionType": "git"
            },
            {
              "lessThan": "bd868c077f67589ed2a714307ceaade5f246e302",
              "status": "affected",
              "version": "2b10cb58d7a3fd621ec9b2ba765a092e562ef998",
              "versionType": "git"
            },
            {
              "lessThan": "c309626bf91fa0a0b583575654e6e14e81f818a3",
              "status": "affected",
              "version": "2b10cb58d7a3fd621ec9b2ba765a092e562ef998",
              "versionType": "git"
            },
            {
              "lessThan": "3b4082fabc67c9780b06eb959e59dd92fa79c0f0",
              "status": "affected",
              "version": "2b10cb58d7a3fd621ec9b2ba765a092e562ef998",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b1dc92f55b22a80ded8f0263c9ef4ba902303895",
              "versionType": "git"
            },
            {
              "lessThan": "6.6.148",
              "status": "affected",
              "version": "6.6.107",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12.101",
              "status": "affected",
              "version": "6.12.48",
              "versionType": "semver"
            },
            {
              "lessThan": "6.17",
              "status": "affected",
              "version": "6.16.8",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "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": "6.6.148",
                  "versionStartIncluding": "6.6.107",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "6.12.48",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.16.8",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu/vcn4: avoid rereading IB param length\n\nReuse the parameter length returned by\nvcn_v4_0_enc_find_ib_param() instead of rereading it from\nthe IB.\n\nThis avoids a potential TOCTOU issue if the IB contents\nchange between reads.\n\n(cherry picked from commit dbb02b4755f8c1f3773263f2d779872c1c0c073a)"
        }
      ],
      "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 flaw is only reachable through the local AMDGPU_CS DRM ioctl on /dev/dri/renderD* (amdgpu_cs_ioctl \u2192 amdgpu_cs_patch_jobs \u2192 amdgpu_cs_patch_ibs), which kmaps the user IB and calls vcn_v4_0_ring_patch_cs_in_place(); no network or physical-device path exists.\nAC:L - patch_cs_in_place reads IB contents directly from attacker-mapped GEM memory without copying; a concurrent thread can change the param-length dword between vcn_v4_0_enc_find_ib_param()\u0027s initial read and the later idx+=amdgpu_ib_get_value(ib,idx)/4, so the attacker controls both sides of the TOCTOU race.\nPR:L - AMDGPU_CS is registered with DRM_AUTH|DRM_RENDER_ALLOW, so any local user who can open the AMDGPU render node (typical render/video group on desktops, gaming handhelds, and GPU cloud instances) can submit VCN4 command buffers without root or init-namespace capabilities.\nUI:N - Exploitation requires only the attacker submitting crafted VCN encode IBs through their own DRM context; no separate victim action such as opening a file, mounting a filesystem, or interacting with malicious content is needed.\nS:C - On VFIO GPU-passthrough and cloud ML hosts, a malicious VM guest submits VCN command streams through the assigned AMD GPU to corrupt host amdgpu kernel state, crossing the guest-to-hypervisor security boundary analogous to a device-model escape.\nC:H - Racing the length dword smaller under-advances IB iteration so nested RADEON_VCN_ENGINE_INFO entries inside a parent package are reached; vcn_v4_0_dec_msg() then reads user-mapped message buffers without snapshotting, enabling TOCTOU check/use mismatches on length/offset fields and out-of-bounds kernel reads past validated bounds.\nI:H - The same nested-entry bypass plus unsnapshotted dec_msg parsing lets userspace rewrite offset/size after kernel validation, driving out-of-bounds accesses in the message loop; skipping vcn_v4_0_limit_sched() via mis-iteration also leaves scheduler/BO state inconsistently modified in attacker-influenceable ways.\nA:H - Racing the length field to zero on re-read makes idx+=0 and re-enters the same ENGINE_INFO entry indefinitely, soft-locking the CS ioctl path; vcn_v4_0_limit_sched() may also block in dma_fence_wait(), yielding repeatable kernel denial-of-service on shared GPU hosts."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T04:58:56.350Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/bbbe6a2a8d8dc87243438d3ffea2083b52d882d9"
        },
        {
          "url": "https://git.kernel.org/stable/c/ff6aa542d91d76a185f69bd1997b94a560ff5f6b"
        },
        {
          "url": "https://git.kernel.org/stable/c/bd868c077f67589ed2a714307ceaade5f246e302"
        },
        {
          "url": "https://git.kernel.org/stable/c/c309626bf91fa0a0b583575654e6e14e81f818a3"
        },
        {
          "url": "https://git.kernel.org/stable/c/3b4082fabc67c9780b06eb959e59dd92fa79c0f0"
        }
      ],
      "title": "drm/amdgpu/vcn4: avoid rereading IB param length",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68107",
    "datePublished": "2026-08-10T11:58:24.135Z",
    "dateReserved": "2026-07-30T09:28:09.368Z",
    "dateUpdated": "2026-08-17T04:58:56.350Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.