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
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 25 Sep 2026 10:30:00 +0000

Type Values Removed Values Added
Description 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
Title net/sched: ets: clamp quantum in parse and fallback paths
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-25T10:23:34.144Z

Reserved: 2026-09-25T10:19:56.068Z

Link: CVE-2026-98009

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-25T11:17:29.210

Modified: 2026-09-25T11:17:29.210

Link: CVE-2026-98009

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-26T03:45:03Z

Weaknesses

No weakness.