net/sched: drr: clamp quantum in change class

Answer in brief

CVE-2026-98010 records a Unknown severity vulnerability in net/sched: drr: clamp quantum in change class. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 25, 2026Updated Sep 25, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 25, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=13d2a1d2b032de08d7dcab6a1edcd47802681f96 <dc8b374214ef5bba4882bbd95b361e42555cfc0d \|\| >=13d2a1d2b032de08d7dcab6a1edcd47802681f96 <d43cded350fe1218493ad3d37a276aff14108ae6 \|\| >=13d2a1d2b032de08d7dcab6a1edcd47802681f96 <8f756ae1c87414ce9cc21b30e6e4c036d6e9e80b \|\| >=13d2a1d2b032de08d7dcab6a1edcd47802681f96 <8382abec0f1568d0a5590d75a3df92f23fcf5196	dc8b374214ef5bba4882bbd95b361e42555cfc0d, d43cded350fe1218493ad3d37a276aff14108ae6, 8f756ae1c87414ce9cc21b30e6e4c036d6e9e80b, 8382abec0f1568d0a5590d75a3df92f23fcf5196
Linux/Linuxgeneric	2.6.29	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to dc8b374214ef5bba4882bbd95b361e42555cfc0d if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

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

Quoted source text, attributed separately from HOL analysis.