Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: fq_pie: clamp quantum in change path fq_pie_change() accepts any quantum value from userspace, including 1. With a crafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1 makes the deficit-refill loop spin ~2^31 times under the qdisc lock (a soft lockup / denial of service). Add max(256U, ...) matching fq_codel_change(). Conditions to recreate the bug: CONFIG_NET_SCH_FQ_PIE=y. Requires CAP_NET_ADMIN (namespace-local via unshare -Urn suffices). tc qdisc add dev dummy0 root fq_pie tc qdisc change dev dummy0 root fq_pie quantum 1 stab data 32768 size_log 15 cell_log 0
References
- https://git.kernel.org/stable/c/215df1e953ae72a09d425ec188e054058ae23dc9
- https://git.kernel.org/stable/c/4864f58c53eb47257d55e01f47d4a9f355f7f970
- https://git.kernel.org/stable/c/6655b56e2801008566c594ef231f6c7b3f716c61
- https://git.kernel.org/stable/c/749aaebc1eb92ce2f38fd3caf68a2f99686d84ef
- https://git.kernel.org/stable/c/8fd98e56c41f79278eeb67512c28d7abc175bcf4
- https://git.kernel.org/stable/c/c11e3a39807eb5a200445ae9082843ab86800415
- https://git.kernel.org/stable/c/f90fe65b977e7aa9eb302230a09eb18f8c32ceaa
- https://git.kernel.org/stable/c/ff4f3a0f3abd2ded467931d7da7984a68a768e0b
FAQ
What is CVE-2026-98013?
CVE-2026-98013 is a documented vulnerability. In the Linux kernel, the following vulnerability has been resolved: net/sched: fq_pie: clamp quantum in change path fq_pie_change() accepts any quantum value from userspace, including 1. With a craf...
How severe is CVE-2026-98013?
CVSS scoring is not yet available for CVE-2026-98013. Check NVD for updates.
Is there a patch for CVE-2026-98013?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.