{
  "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-2025-39845",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-39845",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-09-19T15:26:19.225Z",
    "updatedAt": "2026-10-15T01:08:29.237Z",
    "importedAt": "2026-10-24T01:57:34.152Z",
    "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/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings()",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/mm/64: define ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings()\n\nDefine ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to ensure\npage tables are properly synchronized when calling p*d_populate_kernel().\n\nFor 5-level paging, synchronization is performed via\npgd_populate_kernel().  In 4-level paging, pgd_populate() is a no-op, so\nsynchronization is instead performed at the P4D level via\np4d_populate_kernel().\n\nThis fixes intermittent boot failures on systems using 4-level paging and\na large amount of persistent memory:\n\n  BUG: unable to handle page fault for address: ffffe70000000034\n  #PF: supervisor write access in kernel mode\n  #PF: error_code(0x0002) - not-present page\n  PGD 0 P4D 0\n  Oops: 0002 [#1] SMP NOPTI\n  RIP: 0010:__init_single_page+0x9/0x6d\n  Call Trace:\n   <TASK>\n   __init_zone_device_page+0x17/0x5d\n   memmap_init_zone_device+0x154/0x1bb\n   pagemap_range+0x2e0/0x40f\n   memremap_pages+0x10b/0x2f0\n   devm_memremap_pages+0x1e/0x60\n   dev_dax_probe+0xce/0x2ec [device_dax]\n   dax_bus_probe+0x6d/0xc9\n   [... snip ...]\n   </TASK>\n\nIt also fixes a crash in vmemmap_set_pmd() caused by accessing vmemmap\nbefore sync_global_pgds() [1]:\n\n  BUG: unable to handle page fault for address: ffffeb3ff1200000\n  #PF: supervisor write access in kernel mode\n  #PF: error_code(0x0002) - not-present page\n  PGD 0 P4D 0\n  Oops: Oops: 0002 [#1] PREEMPT SMP NOPTI\n  Tainted: [W]=WARN\n  RIP: 0010:vmemmap_set_pmd+0xff/0x230\n   <TASK>\n   vmemmap_populate_hugepages+0x176/0x180\n   vmemmap_populate+0x34/0x80\n   __populate_section_memmap+0x41/0x90\n   sparse_add_section+0x121/0x3e0\n   __add_pages+0xba/0x150\n   add_pages+0x1d/0x70\n   memremap_pages+0x3dc/0x810\n   devm_memremap_pages+0x1c/0x60\n   xe_devm_add+0x8b/0x100 [xe]\n   xe_tile_init_noalloc+0x6a/0x70 [xe]\n   xe_device_probe+0x48c/0x740 [xe]\n   [... snip ...]",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "8d400913c231bd1da74067255816453f96cd35b0",
              "status": "affected",
              "versionType": "git",
              "lessThan": "744ff519c72de31344a627eaf9b24e9595aae554"
            },
            {
              "version": "8d400913c231bd1da74067255816453f96cd35b0",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5f761d40ee95d2624f839c90ebeef2d5c55007f5"
            },
            {
              "version": "8d400913c231bd1da74067255816453f96cd35b0",
              "status": "affected",
              "versionType": "git",
              "lessThan": "26ff568f390a531d1bd792e49f1a401849921960"
            },
            {
              "version": "8d400913c231bd1da74067255816453f96cd35b0",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b7f4051dd3388edd30e9a6077c05c486aa31e0d4"
            },
            {
              "version": "8d400913c231bd1da74067255816453f96cd35b0",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6bf9473727569e8283c1e2445c7ac42cf4fc9fa9"
            },
            {
              "version": "8d400913c231bd1da74067255816453f96cd35b0",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6659d027998083fbb6d42a165b0c90dc2e8ba989"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.13",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.13"
            },
            {
              "version": "5.15.192",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.151",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.105",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.46",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.16.6",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.16.*"
            },
            {
              "version": "6.17",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}