{"id":"CVE-2026-98011","revision":"9bf5fb31f1a54e3284d5085e85ec26d7","records":[{"revision":"9bf5fb31f1a54e3284d5085e85ec26d7","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98011","aliases":[],"title":"net/sched: hhf: clamp quantum in change and init paths","description":"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 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","state":0,"publishedAt":"2026-09-25T10:23:35.338+00:00","modifiedAt":"2026-10-19T09:12:16.718+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/sched/sch_hhf.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"10239edf86f137ce4c39b62ea9575e8053c549a0\",\n                            \"lessThan\": \"a328698d046098e6f55b3b1460cac6bab577be58\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"10239edf86f137ce4c39b62ea9575e8053c549a0\",\n                            \"lessThan\": \"c364ad3ab3c8a6bce469a5cbf02881ab1324c5da\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"10239edf86f137ce4c39b62ea9575e8053c549a0\",\n                            \"lessThan\": \"2c6dd9fc86d446a03728c43f3b96d9ae29aa058f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"10239edf86f137ce4c39b62ea9575e8053c549a0\",\n                            \"lessThan\": \"6570f326a6a96bedf3d1d1dab6acc9f8c29104ec\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"10239edf86f137ce4c39b62ea9575e8053c549a0\",\n                            \"lessThan\": \"1113b674307ffddd402524bd1fd9d7d5629b705b\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"10239edf86f137ce4c39b62ea9575e8053c549a0\",\n                            \"lessThan\": \"2e77947bbf6c166e76c038663832d0914418f761\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"10239edf86f137ce4c39b62ea9575e8053c549a0\",\n                            \"lessThan\": \"0898c6f9fa9ce2632ae88bd0f34a878ccc6335af\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"10239edf86f137ce4c39b62ea9575e8053c549a0\",\n                            \"lessThan\": \"eb56a495f59baf6cad5ed80e3ffb9078098b1346\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/sched/sch_hhf.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.14\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.14\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.271\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.222\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.189\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.111\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.53\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.7\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/a328698d046098e6f55b3b1460cac6bab577be58","https://git.kernel.org/stable/c/c364ad3ab3c8a6bce469a5cbf02881ab1324c5da","https://git.kernel.org/stable/c/2c6dd9fc86d446a03728c43f3b96d9ae29aa058f","https://git.kernel.org/stable/c/6570f326a6a96bedf3d1d1dab6acc9f8c29104ec","https://git.kernel.org/stable/c/1113b674307ffddd402524bd1fd9d7d5629b705b","https://git.kernel.org/stable/c/2e77947bbf6c166e76c038663832d0914418f761","https://git.kernel.org/stable/c/0898c6f9fa9ce2632ae88bd0f34a878ccc6335af","https://git.kernel.org/stable/c/eb56a495f59baf6cad5ed80e3ffb9078098b1346"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98011","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98011","identifiers":["CVE-2026-98011"]},"retained":false,"historicalAffected":[]}],"coverage":[]}