CVE-2026-68445 (GCVE-0-2026-68445)

Vulnerability from cvelistv5 – Published: 2026-08-12 00:07 – Updated: 2026-08-17 05:05
VLAI
Title
drm/vc4: Prevent shader BO mappings from becoming writable
Summary
In the Linux kernel, the following vulnerability has been resolved: drm/vc4: Prevent shader BO mappings from becoming writable vc4_gem_object_mmap() rejects a writable mapping of a validated shader BO, but leaves VM_MAYWRITE set. Userspace can map the BO read-only and then turn it writable with mprotect(). Validated shader BOs must stay read-only: the validator checks the instructions once and the GPU trusts them afterwards. A writable mapping lets userspace rewrite the code after validation, bypassing the validator. Clear VM_MAYWRITE on the read-only path so the mapping cannot be upgraded, as i915 already does for its read-only objects.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 463873d5701427f2964a0b4b72c45f1f14b6df87 , < 9f0ee411fc2d76333d6087c5862ffa907cf7a175 (git)
Affected: 463873d5701427f2964a0b4b72c45f1f14b6df87 , < 019e6ad247f7fd038d2e009789f6d9bfcccb1ae7 (git)
Affected: 463873d5701427f2964a0b4b72c45f1f14b6df87 , < 6deaa317201851c644c431b57682e54d06b35838 (git)
Affected: 463873d5701427f2964a0b4b72c45f1f14b6df87 , < fe168ef1d232d734d9998fd74822e2e20930dfff (git)
Affected: 463873d5701427f2964a0b4b72c45f1f14b6df87 , < 0c9e6367639548307d3f578f6943ce72c9d39087 (git)
guessed Create a notification for this product.
Linux Linux Affected: 4.5
Unaffected: 0 , < 4.5 (semver)
Unaffected: 6.6.148 , ≤ 6.6.* (semver)
Unaffected: 6.12.101 , ≤ 6.12.* (semver)
Unaffected: 6.18.42 , ≤ 6.18.* (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/vc4/vc4_bo.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9f0ee411fc2d76333d6087c5862ffa907cf7a175",
              "status": "affected",
              "version": "463873d5701427f2964a0b4b72c45f1f14b6df87",
              "versionType": "git"
            },
            {
              "lessThan": "019e6ad247f7fd038d2e009789f6d9bfcccb1ae7",
              "status": "affected",
              "version": "463873d5701427f2964a0b4b72c45f1f14b6df87",
              "versionType": "git"
            },
            {
              "lessThan": "6deaa317201851c644c431b57682e54d06b35838",
              "status": "affected",
              "version": "463873d5701427f2964a0b4b72c45f1f14b6df87",
              "versionType": "git"
            },
            {
              "lessThan": "fe168ef1d232d734d9998fd74822e2e20930dfff",
              "status": "affected",
              "version": "463873d5701427f2964a0b4b72c45f1f14b6df87",
              "versionType": "git"
            },
            {
              "lessThan": "0c9e6367639548307d3f578f6943ce72c9d39087",
              "status": "affected",
              "version": "463873d5701427f2964a0b4b72c45f1f14b6df87",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/gpu/drm/vc4/vc4_bo.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.5"
            },
            {
              "lessThan": "4.5",
              "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": "4.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "4.5",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/vc4: Prevent shader BO mappings from becoming writable\n\nvc4_gem_object_mmap() rejects a writable mapping of a validated shader\nBO, but leaves VM_MAYWRITE set.  Userspace can map the BO read-only and\nthen turn it writable with mprotect().\n\nValidated shader BOs must stay read-only: the validator checks the\ninstructions once and the GPU trusts them afterwards.  A writable\nmapping lets userspace rewrite the code after validation, bypassing the\nvalidator.\n\nClear VM_MAYWRITE on the read-only path so the mapping cannot be\nupgraded, as i915 already does for its read-only objects."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Exploitation requires local access to the vc4 DRM render node (/dev/dri/renderD*) to issue VC4_CREATE_SHADER_BO, VC4_MMAP_BO, mmap/mprotect and VC4_SUBMIT_CL; there is no remote or network-facing path to this code.\nAC:L - The attacker fully controls every step: create a shader that passes validation, map it PROT_READ, upgrade it with mprotect(PROT_WRITE), rewrite the instructions and submit. There is no race, no memory-layout dependency, and it works on the default configuration of any VC4 (Raspberry Pi) system.\nPR:L - VC4_CREATE_SHADER_BO, VC4_MMAP_BO and VC4_SUBMIT_CL are all DRM_RENDER_ALLOW ioctls, so an ordinary unprivileged user with render-node access (the default for logged-in/graphical users on Raspberry Pi and embedded VC4 devices) can perform the whole sequence. No capability check is involved.\nUI:N - The attacking process performs the entire sequence itself; no action by another user or administrator is needed.\nS:U - The vulnerable driver and the compromised resource (kernel/system memory) are both under the kernel\u0027s security authority; this is a standard local kernel privilege escalation rather than a VM or hypervisor boundary escape.\nC:H - Post-validation rewriting of shader code lets the GPU, which has no IOMMU on VC4, read arbitrary system memory via texture, uniform and direct-addressed TMU lookups \u2014 exactly the disclosure the validator exists to prevent, giving arbitrary kernel memory read.\nI:H - Unvalidated QPU code can use the VPM write address register in general-purpose DMA mode to write to arbitrary physical addresses, an arbitrary kernel-memory write primitive that yields full privilege escalation and code execution.\nA:H - The same arbitrary DMA writes and unbounded shader execution readily corrupt kernel structures or hang the GPU, causing kernel panics or a full system hang triggerable at will by an unprivileged user."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:05:42.989Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/9f0ee411fc2d76333d6087c5862ffa907cf7a175"
        },
        {
          "url": "https://git.kernel.org/stable/c/019e6ad247f7fd038d2e009789f6d9bfcccb1ae7"
        },
        {
          "url": "https://git.kernel.org/stable/c/6deaa317201851c644c431b57682e54d06b35838"
        },
        {
          "url": "https://git.kernel.org/stable/c/fe168ef1d232d734d9998fd74822e2e20930dfff"
        },
        {
          "url": "https://git.kernel.org/stable/c/0c9e6367639548307d3f578f6943ce72c9d39087"
        }
      ],
      "title": "drm/vc4: Prevent shader BO mappings from becoming writable",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68445",
    "datePublished": "2026-08-12T00:07:36.230Z",
    "dateReserved": "2026-07-30T09:28:09.394Z",
    "dateUpdated": "2026-08-17T05:05:42.989Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-68445",
      "date": "2026-08-24",
      "epss": "0.00126",
      "percentile": "0.02536"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-68445\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-12T00:17:44.860\",\"lastModified\":\"2026-08-17T06:17:53.560\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\ndrm/vc4: Prevent shader BO mappings from becoming writable\\n\\nvc4_gem_object_mmap() rejects a writable mapping of a validated shader\\nBO, but leaves VM_MAYWRITE set.  Userspace can map the BO read-only and\\nthen turn it writable with mprotect().\\n\\nValidated shader BOs must stay read-only: the validator checks the\\ninstructions once and the GPU trusts them afterwards.  A writable\\nmapping lets userspace rewrite the code after validation, bypassing the\\nvalidator.\\n\\nClear VM_MAYWRITE on the read-only path so the mapping cannot be\\nupgraded, as i915 already does for its read-only objects.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/gpu/drm/vc4/vc4_bo.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"463873d5701427f2964a0b4b72c45f1f14b6df87\",\"lessThan\":\"9f0ee411fc2d76333d6087c5862ffa907cf7a175\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"463873d5701427f2964a0b4b72c45f1f14b6df87\",\"lessThan\":\"019e6ad247f7fd038d2e009789f6d9bfcccb1ae7\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"463873d5701427f2964a0b4b72c45f1f14b6df87\",\"lessThan\":\"6deaa317201851c644c431b57682e54d06b35838\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"463873d5701427f2964a0b4b72c45f1f14b6df87\",\"lessThan\":\"fe168ef1d232d734d9998fd74822e2e20930dfff\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"463873d5701427f2964a0b4b72c45f1f14b6df87\",\"lessThan\":\"0c9e6367639548307d3f578f6943ce72c9d39087\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/gpu/drm/vc4/vc4_bo.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"4.5\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"4.5\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.148\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.101\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.42\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"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/019e6ad247f7fd038d2e009789f6d9bfcccb1ae7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/0c9e6367639548307d3f578f6943ce72c9d39087\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/6deaa317201851c644c431b57682e54d06b35838\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9f0ee411fc2d76333d6087c5862ffa907cf7a175\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/fe168ef1d232d734d9998fd74822e2e20930dfff\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-25T01:21:18+00:00",
      "cve": "CVE-2026-68445",
      "id": "CVE-2026-68445",
      "initial_release_date": "2026-08-12T00:00:00+00:00",
      "product_status:known_affected": "157",
      "product_status:known_not_affected": "119",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: drm/vc4: Prevent shader BO mappings from becoming writable",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68445.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.