CVE-2026-98013

net/sched: fq_pie: clamp quantum in change path

N/A
Published: September 25, 2026 at 10:23 AM UTC
Updated: October 19, 2026 at 10:17 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
N/A
Exploit prediction
EPSS 0.2%

Description

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

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.6ec97ecf1ebe485a17cd8395a5f35e6b80b57665a
Vendor states this is fixed in 215df1e953ae72a09d425ec188e054058ae23dc9 (fixed)
Vendor states this is fixed in 4864f58c53eb47257d55e01f47d4a9f355f7f970 (fixed)
Vendor states this is fixed in 6655b56e2801008566c594ef231f6c7b3f716c61 (fixed)
Vendor states this is fixed in 749aaebc1eb92ce2f38fd3caf68a2f99686d84ef (fixed)
Vendor states this is fixed in 8fd98e56c41f79278eeb67512c28d7abc175bcf4 (fixed)
Vendor states this is fixed in c11e3a39807eb5a200445ae9082843ab86800415 (fixed)
Vendor states this is fixed in f90fe65b977e7aa9eb302230a09eb18f8c32ceaa (fixed)
Vendor states this is fixed in ff4f3a0f3abd2ded467931d7da7984a68a768e0b (fixed)
Vendor states this is fixed in 5.10.271 (unaffected)
Vendor states this is fixed in 5.15.222 (unaffected)
Vendor states this is fixed in 5.6 (unaffected)
Vendor states this is fixed in 6.1.189 (unaffected)
Vendor states this is fixed in 6.12.111 (unaffected)
Vendor states this is fixed in 6.18.53 (unaffected)
Vendor states this is fixed in 6.6.158 (unaffected)
Vendor states this is fixed in 7.2.7 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc3 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

Quick Info

StatusRECEIVED

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