{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-93066",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-93066",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-09-17T16:10:51.612Z",
    "updatedAt": "2026-10-19T09:05:02.188Z",
    "importedAt": "2026-10-24T01:58:35.090Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "x86/mm/pat: Take cpa_lock around large-page collapse",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm/pat: Take cpa_lock around large-page collapse\n\nLoading and unloading modules concurrently on several CPUs on a KASAN\nbuild, with a short delay injected at the CPA page-table lookup to\nwiden the window, faults within minutes:\n\n  BUG: KASAN: use-after-free in __change_page_attr+0x7cc/0x7e0\n  Write of size 8 at addr ffff888181139718 by task modprobe\n  ...\n  The buggy address belongs to the physical page:\n   pfn:0x181139 ... page_type: f2(table)\n\ncpa_collapse_large_pages() rebuilds a leaf PMD from its 4K PTEs and\nfrees the old PTE-table pages, while __change_page_attr() fetches a\nPTE pointer from a lockless lookup_address_in_pgd_attr() and writes\nit with set_pte_atomic() only later. When module text is served from\na shared large ROX mapping the two run on the same PMD:\n\n  CPU A (module load)              CPU B (module finalize)\n  -------------------              -----------------------\n  execmem_make_temp_rw\n   set_memory_nx\n    __change_page_attr\n     split 2M -> 4K table P\n     kpte = &P[i]  (lockless)\n                                   execmem_restore_rox\n                                    set_memory_rox (CPA_COLLAPSE)\n                                     cpa_collapse_large_pages\n                                      rebuild leaf PMD\n                                      flush_tlb_all\n                                      pagetable_free(P)\n     set_pte_atomic(kpte, ...)\n       -> writes into freed P\n\nP is a page-table page (page_type: table), reused at once, so the\nwrite corrupts whatever got the page next: a bad-pte or bad-page\nsplat, or a fatal fault once P has been turned into read-only text.\n\nThe flush_tlb_all() before the free does not close this: its IPI only\nserializes against page-table walkers that run with interrupts off\n(e.g. GUP-fast); the walk in __change_page_attr() runs with interrupts\non, so nothing stops it from holding a stale pointer into P.\n\nSerialize the collapse - the PMD rebuild, TLB flush and PTE-table\nfree - under cpa_lock, the same lock __change_page_attr() now takes\nunconditionally since commit (\"x86/mm/pat: stop gating cpa_lock on\ndebug_pagealloc_enabled()\"), so a concurrent walker can no longer\nhold a pointer into a table the collapse is about to free.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "41d88484c71cd4f659348da41b7b5b3dbd3be1f6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "591b6fac9df3f43522e8ff6eed8662f8b6f1a124"
            },
            {
              "version": "41d88484c71cd4f659348da41b7b5b3dbd3be1f6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "fb97d1d6c20692e15247fa5c8b894b2325e38aee"
            },
            {
              "version": "41d88484c71cd4f659348da41b7b5b3dbd3be1f6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "1aac65f3e651334259ecb2a5f5ddb81c01f02599"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.15",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.15"
            },
            {
              "version": "6.18.52",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.2.6",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "version": "7.3",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}