ptp: vmclock: prevent read-only mappings from becoming writable

{
  "id": "d1f43a675d6a796ae26c25e757dd0f477c05b9cbaacfcdc10bf68c973caaf7c2",
  "url": "https://osv.dev/vulnerability/CVE-2026-80724",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ptp: vmclock: prevent read-only mappings from becoming writable",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ptp: vmclock: prevent read-only mappings from becoming writable vmclock_miscdev_mmap() rejects writable mappings of the shared vmclock ABI page with -EROFS, but leaves VM_MAYWRITE set. Userspace can map the page read-only and then upgrade it to writable with mprotect(), after which the guest can corrupt the host-written timekeeping data (sequence counter, UTC time, TSC offset) that the vmclock ABI defines as read-only. Clear VM_MAYWRITE on the read-only path so the mapping cannot be upgraded, as i915 does for its read-only objects and as fixed in drm/vc4 (CVE-2026-68445) and drm/panthor (CVE-2024-53071).",
    "evidence": "osv:CVE-2026-80724",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.47",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.50",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.11",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.1",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-80724",
      "aliases": [
        "CVE-2026-80724"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "20503272422693d793b84f88bf23fe4e955d3a33"
                },
                {
                  "fixed": "5b4f2bec7bea6c04084d720d731bedee7caf878d"
                },
                {
                  "fixed": "3f5677d2f817355147337f0453174c7bb0f3b66a"
                },
                {
                  "fixed": "2496e141827102d6af512950057d402a2cfb2bfc"
                },
                {
                  "fixed": "2e596e7814ba38cdc129991058b6c254ed37cb11"
                },
                {
                  "fixed": "0ce59c4148ecd1520c5592a63bb3c8991ee2d326"
                },
                {
                  "fixed": "a5edadbae57e2298a56cf7a4e774a027905a331f"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80724.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.47"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "6.18.50"
                },
                {
                  "fixed": "7.1.11"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.2.0"
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                {
                  "fixed": "7.2.1"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.3.0"
                },
                {
                  "fixed": "7.2.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80724.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.609714Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0ce59c4148ecd1520c5592a63bb3c8991ee2d326",
        "https://git.kernel.org/stable/c/2496e141827102d6af512950057d402a2cfb2bfc",
        "https://git.kernel.org/stable/c/2e596e7814ba38cdc129991058b6c254ed37cb11",
        "https://git.kernel.org/stable/c/3f5677d2f817355147337f0453174c7bb0f3b66a",
        "https://git.kernel.org/stable/c/5b4f2bec7bea6c04084d720d731bedee7caf878d",
        "https://git.kernel.org/stable/c/a5edadbae57e2298a56cf7a4e774a027905a331f",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80724.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-80724",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80724.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-80724",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504959,
  "published_at": "2026-08-28T07:03:08.41+00:00"
}