{"api_version":"1","generated_at":"2026-09-26T15:02:10+00:00","cve":"CVE-2026-98011","urls":{"html":"https://cve.report/CVE-2026-98011","api":"https://cve.report/api/cve/CVE-2026-98011.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98011","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98011"},"summary":{"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":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:29","updated_at":"2026-09-25 11:17:29"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/2e77947bbf6c166e76c038663832d0914418f761","name":"https://git.kernel.org/stable/c/2e77947bbf6c166e76c038663832d0914418f761","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1113b674307ffddd402524bd1fd9d7d5629b705b","name":"https://git.kernel.org/stable/c/1113b674307ffddd402524bd1fd9d7d5629b705b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/eb56a495f59baf6cad5ed80e3ffb9078098b1346","name":"https://git.kernel.org/stable/c/eb56a495f59baf6cad5ed80e3ffb9078098b1346","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0898c6f9fa9ce2632ae88bd0f34a878ccc6335af","name":"https://git.kernel.org/stable/c/0898c6f9fa9ce2632ae88bd0f34a878ccc6335af","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98011","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98011","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 10239edf86f137ce4c39b62ea9575e8053c549a0 1113b674307ffddd402524bd1fd9d7d5629b705b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 10239edf86f137ce4c39b62ea9575e8053c549a0 2e77947bbf6c166e76c038663832d0914418f761 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 10239edf86f137ce4c39b62ea9575e8053c549a0 0898c6f9fa9ce2632ae88bd0f34a878ccc6335af git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 10239edf86f137ce4c39b62ea9575e8053c549a0 eb56a495f59baf6cad5ed80e3ffb9078098b1346 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3.14","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 3.14 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.7 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/sched/sch_hhf.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"1113b674307ffddd402524bd1fd9d7d5629b705b","status":"affected","version":"10239edf86f137ce4c39b62ea9575e8053c549a0","versionType":"git"},{"lessThan":"2e77947bbf6c166e76c038663832d0914418f761","status":"affected","version":"10239edf86f137ce4c39b62ea9575e8053c549a0","versionType":"git"},{"lessThan":"0898c6f9fa9ce2632ae88bd0f34a878ccc6335af","status":"affected","version":"10239edf86f137ce4c39b62ea9575e8053c549a0","versionType":"git"},{"lessThan":"eb56a495f59baf6cad5ed80e3ffb9078098b1346","status":"affected","version":"10239edf86f137ce4c39b62ea9575e8053c549a0","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/sched/sch_hhf.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"3.14"},{"lessThan":"3.14","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.111","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.53","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.111","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"3.14","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc3","versionStartIncluding":"3.14","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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"}],"providerMetadata":{"dateUpdated":"2026-09-25T10:23:35.338Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/1113b674307ffddd402524bd1fd9d7d5629b705b"},{"url":"https://git.kernel.org/stable/c/2e77947bbf6c166e76c038663832d0914418f761"},{"url":"https://git.kernel.org/stable/c/0898c6f9fa9ce2632ae88bd0f34a878ccc6335af"},{"url":"https://git.kernel.org/stable/c/eb56a495f59baf6cad5ed80e3ffb9078098b1346"}],"title":"net/sched: hhf: clamp quantum in change and init paths","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98011","datePublished":"2026-09-25T10:23:35.338Z","dateReserved":"2026-09-25T10:19:56.069Z","dateUpdated":"2026-09-25T10:23:35.338Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:29","lastModifiedDate":"2026-09-25 11:17:29","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98011","Ordinal":"1","Title":"net/sched: hhf: clamp quantum in change and init paths","CVE":"CVE-2026-98011","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98011","Ordinal":"1","NoteData":"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","Type":"Description","Title":"net/sched: hhf: clamp quantum in change and init paths"}]}}}