{
  "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-2025-37953",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-37953",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-05-20T16:01:47.818Z",
    "updatedAt": "2026-05-11T21:18:17.815Z",
    "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": "sch_htb: make htb_deactivate() idempotent",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nsch_htb: make htb_deactivate() idempotent\n\nAlan reported a NULL pointer dereference in htb_next_rb_node()\nafter we made htb_qlen_notify() idempotent.\n\nIt turns out in the following case it introduced some regression:\n\nhtb_dequeue_tree():\n  |-> fq_codel_dequeue()\n    |-> qdisc_tree_reduce_backlog()\n      |-> htb_qlen_notify()\n        |-> htb_deactivate()\n  |-> htb_next_rb_node()\n  |-> htb_deactivate()\n\nFor htb_next_rb_node(), after calling the 1st htb_deactivate(), the\nclprio[prio]->ptr could be already set to  NULL, which means\nhtb_next_rb_node() is vulnerable here.\n\nFor htb_deactivate(), although we checked qlen before calling it, in\ncase of qlen==0 after qdisc_tree_reduce_backlog(), we may call it again\nwhich triggers the warning inside.\n\nTo fix the issues here, we need to:\n\n1) Make htb_deactivate() idempotent, that is, simply return if we\n   already call it before.\n2) Make htb_next_rb_node() safe against ptr==NULL.\n\nMany thanks to Alan for testing and for the reproducer.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "e6b45f4de763b00dc1c55e685e2dd1aaf525d3c1",
              "status": "affected",
              "versionType": "git",
              "lessThan": "99ff8a20fd61315bf9ae627440a5ff07d22ee153"
            },
            {
              "version": "32ae12ce6a9f6bace186ca7335220ff59b6cc3cd",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a9945f7cf1709adc5d2d31cb6cfc85627ce299a8"
            },
            {
              "version": "967955c9e57f8eebfccc298037d4aaf3d42bc1c9",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c2d25fddd867ce20a266806634eeeb5c30cb520c"
            },
            {
              "version": "73cf6af13153d62f9b76eff422eea79dbc70f15e",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c928dd4f6bf0c25c72b11824a1e9ac9bd37296a0"
            },
            {
              "version": "bbbf5e0f87078b715e7a665d662a2c0e77f044ae",
              "status": "affected",
              "versionType": "git",
              "lessThan": "31ff70ad39485698cf779f2078132d80b57f6c07"
            },
            {
              "version": "0a188c0e197383683fd093ab1ea6ce9a5869a6ea",
              "status": "affected",
              "versionType": "git",
              "lessThan": "98cd7ed92753090a714f0802d4434314526fe61d"
            },
            {
              "version": "a61f1b5921761fbaf166231418bc1db301e5bf59",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c4792b9e38d2f61b07eac72f10909fa76130314b"
            },
            {
              "version": "5ba8b837b522d7051ef81bacf3d95383ff8edce5",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3769478610135e82b262640252d90f6efb05be71"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "6.1.138",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.1.139"
            },
            {
              "version": "6.6.90",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.6.91"
            },
            {
              "version": "6.12.28",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.12.29"
            },
            {
              "version": "6.14.6",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "6.14.7"
            }
          ]
        }
      ]
    }
  }
}