{
  "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-2021-47623",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47623",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-07-16T11:29:39.071Z",
    "updatedAt": "2026-05-11T13:58:05.571Z",
    "importedAt": "2026-10-24T01:56:36.661Z",
    "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": "powerpc/fixmap: Fix VM debug warning on unmap",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/fixmap: Fix VM debug warning on unmap\n\nUnmapping a fixmap entry is done by calling __set_fixmap()\nwith FIXMAP_PAGE_CLEAR as flags.\n\nToday, powerpc __set_fixmap() calls map_kernel_page().\n\nmap_kernel_page() is not happy when called a second time\nfor the same page.\n\n\tWARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8\n\tCPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682\n\tNIP:  c0017cd4 LR: c00187f0 CTR: 00000010\n\tREGS: e1011d50 TRAP: 0700   Not tainted  (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty)\n\tMSR:  00029032 <EE,ME,IR,DR,RI>  CR: 42000208  XER: 00000000\n\n\tGPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c\n\tGPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000\n\tGPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000\n\tGPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000\n\tNIP [c0017cd4] set_pte_at+0xc/0x1e8\n\tLR [c00187f0] map_kernel_page+0x9c/0x100\n\tCall Trace:\n\t[e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable)\n\t[e1011e30] [c0165fec] __set_fixmap+0x30/0x44\n\t[e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170\n\t[e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0\n\t[e1011e90] [c0c03634] do_one_initcall+0x80/0x178\n\t[e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250\n\t[e1011f20] [c0007e34] kernel_init+0x24/0x140\n\t[e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64\n\tInstruction dump:\n\t7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010\n\t4e800020 81250000 712a0001 41820008 <0fe00000> 9421ffe0 93e1001c 48000030\n\nImplement unmap_kernel_page() which clears an existing pte.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "265c3491c4bc8d40587996d6ee2f447a7ccfb4f3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "67baac10dd5ad1e9f50e8f2659984b3b0728d54e"
            },
            {
              "version": "265c3491c4bc8d40587996d6ee2f447a7ccfb4f3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "43ae0ccc4d2722b833fb59b905af129428e06d03"
            },
            {
              "version": "265c3491c4bc8d40587996d6ee2f447a7ccfb4f3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "033fd42c18d9b2121595b6f1e8419a115f9ac5b7"
            },
            {
              "version": "265c3491c4bc8d40587996d6ee2f447a7ccfb4f3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "aec982603aa8cc0a21143681feb5f60ecc69d718"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.5",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.5"
            },
            {
              "version": "5.10.101",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.24",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "5.16.10",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.16.*"
            },
            {
              "version": "5.17",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}