CVE-2026-80724

Full vulnerability record from the local CVENow database.

Description

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).

Severity

HIGH

CVSS score

8.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-08-28 08:16:58.210000

Last modified

2026-10-19 09:17:09.397000

View original CVE JSON

{
  "id": "CVE-2026-80724",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-28T08:16:58.210",
  "lastModified": "2026-10-19T09:17:09.397",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nptp: vmclock: prevent read-only mappings from becoming writable\n\nvmclock_miscdev_mmap() rejects writable mappings of the shared vmclock\nABI page with -EROFS, but leaves VM_MAYWRITE set.  Userspace can map the\npage read-only and then upgrade it to writable with mprotect(), after\nwhich the guest can corrupt the host-written timekeeping data (sequence\ncounter, UTC time, TSC offset) that the vmclock ABI defines as read-only.\n\nClear VM_MAYWRITE on the read-only path so the mapping cannot be\nupgraded, as i915 does for its read-only objects and as fixed in drm/vc4\n(CVE-2026-68445) and drm/panthor (CVE-2024-53071)."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/ptp/ptp_vmclock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "20503272422693d793b84f88bf23fe4e955d3a33",
              "lessThan": "5b4f2bec7bea6c04084d720d731bedee7caf878d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "20503272422693d793b84f88bf23fe4e955d3a33",
              "lessThan": "3f5677d2f817355147337f0453174c7bb0f3b66a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "20503272422693d793b84f88bf23fe4e955d3a33",
              "lessThan": "2496e141827102d6af512950057d402a2cfb2bfc",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "20503272422693d793b84f88bf23fe4e955d3a33",
              "lessThan": "2e596e7814ba38cdc129991058b6c254ed37cb11",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "20503272422693d793b84f88bf23fe4e955d3a33",
              "lessThan": "0ce59c4148ecd1520c5592a63bb3c8991ee2d326",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "20503272422693d793b84f88bf23fe4e955d3a33",
              "lessThan": "a5edadbae57e2298a56cf7a4e774a027905a331f",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/ptp/ptp_vmclock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.13",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.13",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.47",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.50",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.11",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.1",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.4",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "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:C/C:H/I:H/A:H",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.0,
        "impactScore": 6.0
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0ce59c4148ecd1520c5592a63bb3c8991ee2d326",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2496e141827102d6af512950057d402a2cfb2bfc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2e596e7814ba38cdc129991058b6c254ed37cb11",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/3f5677d2f817355147337f0453174c7bb0f3b66a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5b4f2bec7bea6c04084d720d731bedee7caf878d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a5edadbae57e2298a56cf7a4e774a027905a331f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}