CVE-2026-98009

In the Linux kernel, the following vulnerability has been resolved:

net/sched: ets: clamp quantum in parse and fallback paths

ets qdisc change() falls back to psched mtu() with no floor for bands without an explicit quantum. With a crafted size table qdisc pkt len reaches ~2 GiB, so a zero psched mtu on a headerless device makes the deficit-refill loop spin under the qdisc lock.

Move the floor into ets quantum parse() so explicitly configured quanta are also clamped to [256, 1<<20], not just the fallback path.

Conditions to recreate the bug: CONFIG NET SCH ETS=y. Requires CAP NET ADMIN (namespace-local via unshare -Urn suffices).

tc qdisc add dev dummy0 root ets bands 3 strict 2 quanta 1 1