CVE-2026-98013

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