CVE-2026-98010

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

net/sched: drr: clamp quantum in change class

drr change class() rejects explicit quantum==0 but falls back to psched mtu() with no floor. With a crafted size table qdisc pkt len reaches ~2 GiB, so quantum=1 (or a zero psched mtu on a headerless device) makes the deficit-refill loop spin under the qdisc lock.

Add clamp t(u32, quantum, 256, 1<<20) after the zero reject and on the fallback path. The explicit-zero reject is preserved.

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

tc qdisc add dev dummy0 root drr tc class add dev dummy0 parent 1: classid 1:1 drr quantum 1