{
  "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-2021-46990",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-46990",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-02-28T08:13:16.569Z",
    "updatedAt": "2026-05-23T15:18:54.715Z",
    "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/64s: Fix crashes when toggling entry flush barrier",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/64s: Fix crashes when toggling entry flush barrier\n\nThe entry flush mitigation can be enabled/disabled at runtime via a\ndebugfs file (entry_flush), which causes the kernel to patch itself to\nenable/disable the relevant mitigations.\n\nHowever depending on which mitigation we're using, it may not be safe to\ndo that patching while other CPUs are active. For example the following\ncrash:\n\n  sleeper[15639]: segfault (11) at c000000000004c20 nip c000000000004c20 lr c000000000004c20\n\nShows that we returned to userspace with a corrupted LR that points into\nthe kernel, due to executing the partially patched call to the fallback\nentry flush (ie. we missed the LR restore).\n\nFix it by doing the patching under stop machine. The CPUs that aren't\ndoing the patching will be spinning in the core of the stop machine\nlogic. That is currently sufficient for our purposes, because none of\nthe patching we do is to that code or anywhere in the vicinity.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "4a1e90af718d1489ffcecc8f52486c4f5dc0f7a6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "8382b15864e5014261b4f36c2aa89723612ee058"
            },
            {
              "version": "fa4bf9f38184ed7ca4916eb64f8c767d1e279c1f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0c25a7bb697f2e6ee65b6d63782f675bf129511a"
            },
            {
              "version": "db01cad9efe3c3838a6b3a3f68affd295c4b92d6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ee4b7aab93c2631c3bb0753023c5dda592bb666b"
            },
            {
              "version": "f69bb4e51f41973fb7594be1479fa689831efe1a",
              "status": "affected",
              "versionType": "git",
              "lessThan": "2db22ba4e0e103f00e0512e0ecce36ac78c644f8"
            },
            {
              "version": "b65458b6be8032c5179d4f562038575d7b3a6be3",
              "status": "affected",
              "versionType": "git",
              "lessThan": "0b4eb172cc12dc102cd0ad013e53ee4463db9508"
            },
            {
              "version": "f79643787e0a0762d2409b7b8334e83f22d85695",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d2e3590ca39ccfd8a5a46d8c7f095cb6c7b9ae92"
            },
            {
              "version": "f79643787e0a0762d2409b7b8334e83f22d85695",
              "status": "affected",
              "versionType": "git",
              "lessThan": "dd0d6117052faace5440db20fc37175efe921c7d"
            },
            {
              "version": "f79643787e0a0762d2409b7b8334e83f22d85695",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5bc00fdda1e934c557351a9c751a205293e68cbf"
            },
            {
              "version": "f79643787e0a0762d2409b7b8334e83f22d85695",
              "status": "affected",
              "versionType": "git",
              "lessThan": "aec86b052df6541cc97c5fca44e5934cbea4963b"
            },
            {
              "version": "e590b36718d6e740b7b19514f710402a6499164c",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "4.4.245",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.4.269"
            },
            {
              "version": "4.9.245",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.9.269"
            },
            {
              "version": "4.14.208",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.14.233"
            },
            {
              "version": "4.19.159",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.19.191"
            },
            {
              "version": "5.4.79",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "5.4.120"
            },
            {
              "version": "5.9.10",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "5.10"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.10",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.10"
            },
            {
              "version": "4.4.269",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.4.*"
            },
            {
              "version": "4.9.269",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.9.*"
            },
            {
              "version": "4.14.233",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.14.*"
            },
            {
              "version": "4.19.191",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "4.19.*"
            },
            {
              "version": "5.4.120",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.38",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.11.22",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.11.*"
            },
            {
              "version": "5.12.5",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.12.*"
            },
            {
              "version": "5.13",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}