{
  "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-2025-37856",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-37856",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-05-09T06:42:04.315Z",
    "updatedAt": "2026-10-21T12:36:30.528Z",
    "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": "btrfs: harden block_group::bg_list against list_del() races",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: harden block_group::bg_list against list_del() races\n\nAs far as I can tell, these calls of list_del_init() on bg_list cannot\nrun concurrently with btrfs_mark_bg_unused() or btrfs_mark_bg_to_reclaim(),\nas they are in transaction error paths and situations where the block\ngroup is readonly.\n\nHowever, if there is any chance at all of racing with mark_bg_unused(),\nor a different future user of bg_list, better to be safe than sorry.\n\nOtherwise we risk the following interleaving (bg_list refcount in parens)\n\nT1 (some random op)                       T2 (btrfs_mark_bg_unused)\n                                        !list_empty(&bg->bg_list); (1)\nlist_del_init(&bg->bg_list); (1)\n                                        list_move_tail (1)\nbtrfs_put_block_group (0)\n                                        btrfs_delete_unused_bgs\n                                             bg = list_first_entry\n                                             list_del_init(&bg->bg_list);\n                                             btrfs_put_block_group(bg); (-1)\n\nUltimately, this results in a broken ref count that hits zero one deref\nearly and the real final deref underflows the refcount, resulting in a WARNING.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "a9f189716cf15913c453299d72f69c51a9b0f86b",
              "status": "affected",
              "versionType": "git",
              "lessThan": "9039afe6240ae01d6caf2fa731590ac74fb8a69b"
            },
            {
              "version": "a9f189716cf15913c453299d72f69c51a9b0f86b",
              "status": "affected",
              "versionType": "git",
              "lessThan": "bf089c4d1141b27332c092b1dcca5022c415a3b6"
            },
            {
              "version": "a9f189716cf15913c453299d72f69c51a9b0f86b",
              "status": "affected",
              "versionType": "git",
              "lessThan": "909e60fb469d4101c6b08cf6e622efb062bb24a1"
            },
            {
              "version": "a9f189716cf15913c453299d72f69c51a9b0f86b",
              "status": "affected",
              "versionType": "git",
              "lessThan": "185fd73e5ac06027c4be9a129e59193f6a3ef202"
            },
            {
              "version": "a9f189716cf15913c453299d72f69c51a9b0f86b",
              "status": "affected",
              "versionType": "git",
              "lessThan": "7511e29cf1355b2c47d0effb39e463119913e2f6"
            },
            {
              "version": "edf3b5aadb2515c808200b904baa5b70a727f0ac",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "01eca70ef8cf499d0cb6d1bbd691558e7792cf17",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "5d19abcffd8404078dfa7d7118cec357b5e7bc58",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "5.15.128",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "5.16"
            },
            {
              "version": "6.1.47",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.2"
            },
            {
              "version": "6.4.12",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.5"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.5",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.5"
            },
            {
              "version": "6.6.160",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.24",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.13.12",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.13.*"
            },
            {
              "version": "6.14.3",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.14.*"
            },
            {
              "version": "6.15",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}