{"id":"CVE-2026-98011","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: hhf: clamp quantum in change and init paths\n\nhhf_change() accepts any quantum from userspace, including 1","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: hhf: clamp quantum in change and init paths\n\nhhf_change() accepts any quantum from userspace, including 1. With a\ncrafted size table qdisc_pkt_len reaches ~2…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 < 1113b674307ffddd402524bd1fd9d7d5629b705b","Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 < 2e77947bbf6c166e76c038663832d0914418f761","Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 < 0898c6f9fa9ce2632ae88bd0f34a878ccc6335af","Linux >= 10239edf86f137ce4c39b62ea9575e8053c549a0 < eb56a495f59baf6cad5ed80e3ffb9078098b1346","Linux 3.14"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:29.427","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98011","references":[{"url":"https://git.kernel.org/stable/c/0898c6f9fa9ce2632ae88bd0f34a878ccc6335af","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1113b674307ffddd402524bd1fd9d7d5629b705b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2e77947bbf6c166e76c038663832d0914418f761","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/eb56a495f59baf6cad5ed80e3ffb9078098b1346","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.859Z","slug":"CVE-2026-98011","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: hhf: clamp quantum in change and init paths\n\nhhf_change() accepts any quantum from userspace, including 1. With a\ncrafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1 makes\nthe deficit-refill loop spin ~2^31 times under the qdisc lock\n(a soft lockup / denial of service).\n\nAdd max(256U, ...) in hhf_change() matching fq_codel_change(). Clamp\nhhf_init() to [256, 1<<20] matching the siblings, and remove the old\nfallback that only set quantum=256 on overflow.\n\nConditions to recreate the bug:\n  CONFIG_NET_SCH_HHF=y. Requires CAP_NET_ADMIN (namespace-local via\n  unshare -Urn suffices).\n\n  tc qdisc add dev dummy0 root hhf\n  tc qdisc change dev dummy0 root hhf quantum 1 stab data 32768 size_log 15 cell_log 0\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}