net/sched: hhf: clamp quantum before hhf_change() to avoid overflow

{
  "id": "cc141f109d76983bbf6657738a0a5ee8850f8720edae14ca1e48b2c456d53862",
  "url": "https://osv.dev/vulnerability/CVE-2026-90073",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/sched: hhf: clamp quantum before hhf_change() to avoid overflow",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/sched: hhf: clamp quantum before hhf_change() to avoid overflow hhf_init() sets q->quantum = psched_mtu(qdisc_dev(sch)) with no overflow check. A device with a huge MTU (e.g. dummy with max_mtu == 0 accepting MTU 2147483634) makes weight * quantum overflow the signed deficit in hhf_dequeue(), spinning forever. Clamp q->quantum before hhf_change() so both the opt and !opt paths see a sane quantum. Without this, bare \"tc qdisc add ... hhf\" succeeds with a clamped quantum but \"tc qdisc add ... hhf limit 1000\" (any option present) fails with -EINVAL because hhf_change() re-validates the unclamped default (sch_hhf.c:559). 256 matches fq_codel's floor and is a sane minimum for a DRR quantum. Conditions to recreate the bug: a device whose MTU (plus hard_header_len) wraps psched_mtu() into the sign bit (e.g. a dummy device with max_mtu == 0 accepting MTU 2147483634). Requires CAP_NET_ADMIN in a user namespace.",
    "evidence": "osv:CVE-2026-90073",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.270",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.221",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.188",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.157",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.110",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.52",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-90073",
      "aliases": [
        "CVE-2026-90073"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "10239edf86f137ce4c39b62ea9575e8053c549a0"
                },
                {
                  "fixed": "2e0f0729f922c8de13801004e2131b57646c7c5f"
                },
                {
                  "fixed": "0c66223e90ddb4fd3700965a9241f2fde7bd6bc7"
                },
                {
                  "fixed": "20b65bf7ca06e48ec1d62ed8012f71205328dbe4"
                },
                {
                  "fixed": "dea2789a9d5ff38bdd77f2e64d550430899e2839"
                },
                {
                  "fixed": "fa9c2055f0a60f801ccf286af53d387dc6202c3f"
                },
                {
                  "fixed": "99770b5d8e0e1c69b996f74a19d71afd2c4a9aa4"
                },
                {
                  "fixed": "2446644b0f6d045b01db6acbaf55552dbec8a59a"
                },
                {
                  "fixed": "2164b512b97bb053e8ce4d6e95576f11bed6a005"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90073.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "3.14.0"
                },
                {
                  "fixed": "5.10.270"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.11.0"
                },
                {
                  "fixed": "5.15.221"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "6.1.188"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.2.0"
                },
                {
                  "fixed": "6.6.157"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.12.110"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.52"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.6"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90073.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.038630388Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0c66223e90ddb4fd3700965a9241f2fde7bd6bc7",
        "https://git.kernel.org/stable/c/20b65bf7ca06e48ec1d62ed8012f71205328dbe4",
        "https://git.kernel.org/stable/c/2164b512b97bb053e8ce4d6e95576f11bed6a005",
        "https://git.kernel.org/stable/c/2446644b0f6d045b01db6acbaf55552dbec8a59a",
        "https://git.kernel.org/stable/c/2e0f0729f922c8de13801004e2131b57646c7c5f",
        "https://git.kernel.org/stable/c/99770b5d8e0e1c69b996f74a19d71afd2c4a9aa4",
        "https://git.kernel.org/stable/c/dea2789a9d5ff38bdd77f2e64d550430899e2839",
        "https://git.kernel.org/stable/c/fa9c2055f0a60f801ccf286af53d387dc6202c3f",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90073.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-90073",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90073.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-90073",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 493591,
  "published_at": "2026-09-17T16:05:53.562+00:00"
}