net: cap tx_queue_len at S16_MAX to prevent oversized ring allocations

{
  "id": "d097e604c2c68ecfbc59d446e5bce41e7b06e5850a314b7608830b02718caaa3",
  "url": "https://osv.dev/vulnerability/CVE-2026-98022",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net: cap tx_queue_len at S16_MAX to prevent oversized ring allocations",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net: cap tx_queue_len at S16_MAX to prevent oversized ring allocations Several subsystems allocate ring buffers sized by dev->tx_queue_len with no upper bound. An unprivileged user (via unshare -Urn) can set a huge tx_queue_len and exhaust global memory with ring allocations: - pfifo_fast: pfifo_fast_init() and pfifo_fast_change_tx_queue_len() allocate 3 skb_array rings of tx_queue_len entries each. - tun: tun_queue_resize() and the queue-attach path resize ptr_rings to tx_queue_len on the NETDEV_CHANGE_TX_QUEUE_LEN notifier. - tap (macvtap/ipvtap): tap_queue_resize() and tap_init() resize/init ptr_rings to tx_queue_len on the same notifier. netif_change_tx_queue_len() is the single entry point for IFLA_TXQLEN, sysfs, and the SIOCSIFTXQLEN ioctl. Cap new_len at S16_MAX (32767) there so the oversized value is rejected at set time. This takes effect whether the device is up or down, before dev->tx_queue_len is written, before any notifier fires, and before any ring is allocated. The \"> S16_MAX\" check also subsumes the previous unsigned-long truncation test, and a negative ifr_qlen from the ioctl lands far above the cap after conversion, so both old failure modes are covered by the one comparison. tx_queue_len is ambigious: both a per-ring sizing multiplier and a default queue-length/limit knob for consumers that allocate nothing at set time (pfifo/bfifo/gred/plug/sfb limits, htb direct_qlen, qfq max_classes, te",
    "evidence": "osv:CVE-2026-98022",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.10.271",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.15.222",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.189",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.158",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.111",
            "evidence": "/affected/1/ranges"
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          {
            "value": "6.18.53",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.7",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98022",
      "aliases": [
        "CVE-2026-98022"
      ],
      "affected": [
        {
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                  "fixed": "24d02c909a1725ab9eceb92db7d02e4e841f17ca"
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                {
                  "fixed": "5e5591a0f33f7c11bf1d338dbb6c5072575de64c"
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                {
                  "fixed": "c8d4060610c69645733c92d94fceb4b93808ac4d"
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                {
                  "fixed": "c2362c500931e5bd1826bce34e9ce28af80e7541"
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                {
                  "fixed": "81c0e02076989743a603806a5a4f44d2c40dc01f"
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                  "fixed": "081340cf70a789b94b4174af54a63ffd49677a4e"
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          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98022.json"
          }
        },
        {
          "ranges": [
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              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.16.0"
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                {
                  "fixed": "5.10.271"
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98022.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.861504534Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/081340cf70a789b94b4174af54a63ffd49677a4e",
        "https://git.kernel.org/stable/c/24d02c909a1725ab9eceb92db7d02e4e841f17ca",
        "https://git.kernel.org/stable/c/5e5591a0f33f7c11bf1d338dbb6c5072575de64c",
        "https://git.kernel.org/stable/c/66ab4c59b74db7ab53a1c9083feaaede393a96a0",
        "https://git.kernel.org/stable/c/81c0e02076989743a603806a5a4f44d2c40dc01f",
        "https://git.kernel.org/stable/c/a03b927bae4af5c23fd5315a237855c17cc8f422",
        "https://git.kernel.org/stable/c/c2362c500931e5bd1826bce34e9ce28af80e7541",
        "https://git.kernel.org/stable/c/c8d4060610c69645733c92d94fceb4b93808ac4d",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98022.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98022",
        "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/2026/98xxx/CVE-2026-98022.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98022",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 505373,
  "published_at": "2026-09-25T10:23:42.116+00:00"
}