FKIE_CVE-2026-98013

Vulnerability from fkie_nvd - Published: 2026-09-25 11:17 - Updated: 2026-09-25 11:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: fq_pie: clamp quantum in change path fq_pie_change() accepts any quantum value from userspace, including 1. With a crafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1 makes the deficit-refill loop spin ~2^31 times under the qdisc lock (a soft lockup / denial of service). Add max(256U, ...) matching fq_codel_change(). Conditions to recreate the bug: CONFIG_NET_SCH_FQ_PIE=y. Requires CAP_NET_ADMIN (namespace-local via unshare -Urn suffices). tc qdisc add dev dummy0 root fq_pie tc qdisc change dev dummy0 root fq_pie quantum 1 stab data 32768 size_log 15 cell_log 0
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4864f58c53eb47257d55e01f47d4a9f355f7f970
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6655b56e2801008566c594ef231f6c7b3f716c61
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c11e3a39807eb5a200445ae9082843ab86800415
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f90fe65b977e7aa9eb302230a09eb18f8c32ceaa
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_fq_pie.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "f90fe65b977e7aa9eb302230a09eb18f8c32ceaa",
              "status": "affected",
              "version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
              "versionType": "git"
            },
            {
              "lessThan": "c11e3a39807eb5a200445ae9082843ab86800415",
              "status": "affected",
              "version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
              "versionType": "git"
            },
            {
              "lessThan": "6655b56e2801008566c594ef231f6c7b3f716c61",
              "status": "affected",
              "version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
              "versionType": "git"
            },
            {
              "lessThan": "4864f58c53eb47257d55e01f47d4a9f355f7f970",
              "status": "affected",
              "version": "ec97ecf1ebe485a17cd8395a5f35e6b80b57665a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_fq_pie.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.6"
            },
            {
              "lessThan": "5.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fq_pie: clamp quantum in change path\n\nfq_pie_change() accepts any quantum value from userspace, including 1.\nWith a crafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1\nmakes the deficit-refill loop spin ~2^31 times under the qdisc lock\n(a soft lockup / denial of service).\n\nAdd max(256U, ...) matching fq_codel_change().\n\nConditions to recreate the bug:\n  CONFIG_NET_SCH_FQ_PIE=y. Requires CAP_NET_ADMIN (namespace-local via\n  unshare -Urn suffices).\n\n  tc qdisc add dev dummy0 root fq_pie\n  tc qdisc change dev dummy0 root fq_pie quantum 1 stab data 32768 size_log 15 cell_log 0"
    }
  ],
  "id": "CVE-2026-98013",
  "lastModified": "2026-09-25T11:17:29.660",
  "metrics": {},
  "published": "2026-09-25T11:17:29.660",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4864f58c53eb47257d55e01f47d4a9f355f7f970"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6655b56e2801008566c594ef231f6c7b3f716c61"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c11e3a39807eb5a200445ae9082843ab86800415"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f90fe65b977e7aa9eb302230a09eb18f8c32ceaa"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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