GHSA-8q45-3gcx-v6jhunknown

In the Linux kernel, the following vulnerability has been resolved: net/sched: fq_pie: clamp...

Published
September 25, 2026
Last Modified
October 3, 2026

🔗 CVE IDs covered (1)

📋 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

🔗 References (10)