{
  "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-2021-47493",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47493",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2024-05-22T08:19:41.419Z",
    "updatedAt": "2026-08-05T08:48:03.801Z",
    "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": "ocfs2: fix race between searching chunks and release journal_head from buffer_head",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix race between searching chunks and release journal_head from buffer_head\n\nEncountered a race between ocfs2_test_bg_bit_allocatable() and\njbd2_journal_put_journal_head() resulting in the below vmcore.\n\n  PID: 106879  TASK: ffff880244ba9c00  CPU: 2   COMMAND: \"loop3\"\n  Call trace:\n    panic\n    oops_end\n    no_context\n    __bad_area_nosemaphore\n    bad_area_nosemaphore\n    __do_page_fault\n    do_page_fault\n    page_fault\n      [exception RIP: ocfs2_block_group_find_clear_bits+316]\n    ocfs2_block_group_find_clear_bits [ocfs2]\n    ocfs2_cluster_group_search [ocfs2]\n    ocfs2_search_chain [ocfs2]\n    ocfs2_claim_suballoc_bits [ocfs2]\n    __ocfs2_claim_clusters [ocfs2]\n    ocfs2_claim_clusters [ocfs2]\n    ocfs2_local_alloc_slide_window [ocfs2]\n    ocfs2_reserve_local_alloc_bits [ocfs2]\n    ocfs2_reserve_clusters_with_limit [ocfs2]\n    ocfs2_reserve_clusters [ocfs2]\n    ocfs2_lock_refcount_allocators [ocfs2]\n    ocfs2_make_clusters_writable [ocfs2]\n    ocfs2_replace_cow [ocfs2]\n    ocfs2_refcount_cow [ocfs2]\n    ocfs2_file_write_iter [ocfs2]\n    lo_rw_aio\n    loop_queue_work\n    kthread_worker_fn\n    kthread\n    ret_from_fork\n\nWhen ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the\nbg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and\nreleased the jounal head from the buffer head.  Needed to take bit lock\nfor the bit 'BH_JournalHead' to fix this race.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5043fbd294f5909a080ade0f04b70a4da9e122b7"
            },
            {
              "version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c",
              "status": "affected",
              "versionType": "git",
              "lessThan": "2e382600e8856ea654677b5134ee66e03ea72bc2"
            },
            {
              "version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6f1b228529ae49b0f85ab89bcdb6c365df401558"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "2.6.16",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "2.6.16"
            },
            {
              "version": "5.10.77",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.14.16",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.14.*"
            },
            {
              "version": "5.15",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}