CVE Catalog

CVE-2026-98009

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the ets network scheduler lacked a lower bound on the quantum value. With a crafted size table qdisc_pkt_len can reach ~2 GiB, and a zero psched_mtu on a headerless device makes the deficit-refill loop spin under the qdisc lock. The fix moves the floor into ets_quantum_parse() so explicitly configured quanta are also clamped to [256, 1<<20].

Risk Assessment

A local user with CAP_NET_ADMIN privileges (namespace-local via unshare -Urn suffices) can cause a hang or kernel panic by stalling the qdisc. This can lead to denial of service on the affected host.

Recommendation

Update the Linux kernel to a version containing the fix. Restrict granting of CAP_NET_ADMIN to trusted users and processes.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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

Vulnerability data from NVD (NIST) · CISA KEV · EPSS