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CVE-2026-98009

Updated on 25 Sep 2026

Severity

5.5 Medium severity

Details

CVSS score
5.5
Links
NISTCIRCLRHELUbuntu

Overview

About vulnerability

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

Details

Affected product:
AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 11 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU
Affected packages:
kernel @ 5.10.0 (+7 more)

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 12 Planned —
Debian 13 Released
17 kernels
  • 6.12.85-1
  • 6.12.86-1
  • 6.12.88-1
  • 6.12.74-2
  • 6.12.73-1
  • 6.12.63-1
  • 6.12.69-1
  • 6.12.74-1
  • 6.12.90-1
  • 6.12.90-2
  • 6.12.94-1
  • 6.12.95-1
  • 6.12.96-1
  • 6.12.100-1
  • 6.12.101-1
  • 6.12.105-1
  • 6.12.107-1