{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98234", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.329Z", "datePublished": "2026-10-06T08:45:07.215Z", "dateUpdated": "2026-10-19T09:16:06.128Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:16:06.128Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: hhf: cap hh_flows_limit at change time\n\nhhf_change() stores TCA_HHF_HH_FLOWS_LIMIT with no upper bound. A huge\nhh_flows_limit lets each new heavy-hitter flow pass the\nhh_flows_current_cnt check in alloc_new_hh() and forces a fixed-size\nkzalloc(GFP_ATOMIC) per flow under spoofed traffic, for unbounded memory\ngrowth.\n\nBound the attribute with NLA_POLICY_MAX() at 2*HH_FLOWS_CNT (the\nhhf_init() default) and report the rejected value via extack. The\ndeprecated nested parse is kept: legacy tc does not set NLA_F_NESTED on\nTCA_OPTIONS. Configs relying on hh_limit above the default were relying\non unbounded, unsafe behaviour and are not supported going forward.\n\nhhf_init() also ran hhf_change() before setting the default\nhh_flows_limit, so a user-supplied hh_limit at add time was clobbered\nback to 2048. Set the default before hhf_change() so the configured\nvalue sticks.\n\nThis is a follow-up to commit eb56a495f59b (\"net/sched: hhf: clamp\nquantum in change and init paths\"), which bounded the quantum of the\nsame qdisc; the hh_flows_limit bound is the remaining unbounded knob of\nthat series' scope.\n\nConditions to recreate the bug: CAP_NET_ADMIN in a user namespace;\ntc qdisc change dev X root hhf hh_limit 4294967295 succeeds and the\nvalue is echoed by tc qdisc show, unbounding heavy-hitter flow\nallocations; also tc qdisc add dev X root hhf hh_limit 500 stores 2048\ninstead of 500." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_hhf.c" ], "versions": [ { "version": "10239edf86f137ce4c39b62ea9575e8053c549a0", "lessThan": "7adfd0a42174b85c6bd678858ecd6674f403f336", "status": "affected", "versionType": "git" }, { "version": "10239edf86f137ce4c39b62ea9575e8053c549a0", "lessThan": "35fd423a5c5132c6f4321f6c4f0a7b4b90af830c", "status": "affected", "versionType": "git" }, { "version": "10239edf86f137ce4c39b62ea9575e8053c549a0", "lessThan": "06d2a101e89063cb0b9b459104db48bdfb0a797d", "status": "affected", "versionType": "git" }, { "version": "10239edf86f137ce4c39b62ea9575e8053c549a0", "lessThan": "d8e2f1f0263b7c97b222c06070cccf13e0ab7112", "status": "affected", "versionType": "git" }, { "version": "10239edf86f137ce4c39b62ea9575e8053c549a0", "lessThan": "f3f4a5cb4a6e9b1f1f25d34dfc25f836a1601db4", "status": "affected", "versionType": "git" }, { "version": "10239edf86f137ce4c39b62ea9575e8053c549a0", "lessThan": "1731ff1d20489afe4cd01b7d16d37f324746ac54", "status": "affected", "versionType": "git" }, { "version": "10239edf86f137ce4c39b62ea9575e8053c549a0", "lessThan": "f6547d27ce2093c5627636fb63dd0b7523c466f9", "status": "affected", "versionType": "git" }, { "version": "10239edf86f137ce4c39b62ea9575e8053c549a0", "lessThan": "2cef2588c995722a901368def30befeef9ae55c6", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/sched/sch_hhf.c" ], "versions": [ { "version": "3.14", "status": "affected" }, { "version": "0", "lessThan": "3.14", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.271", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.54", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.8", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "5.10.271" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "6.18.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "7.2.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.14", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/7adfd0a42174b85c6bd678858ecd6674f403f336" }, { "url": "https://git.kernel.org/stable/c/35fd423a5c5132c6f4321f6c4f0a7b4b90af830c" }, { "url": "https://git.kernel.org/stable/c/06d2a101e89063cb0b9b459104db48bdfb0a797d" }, { "url": "https://git.kernel.org/stable/c/d8e2f1f0263b7c97b222c06070cccf13e0ab7112" }, { "url": "https://git.kernel.org/stable/c/f3f4a5cb4a6e9b1f1f25d34dfc25f836a1601db4" }, { "url": "https://git.kernel.org/stable/c/1731ff1d20489afe4cd01b7d16d37f324746ac54" }, { "url": "https://git.kernel.org/stable/c/f6547d27ce2093c5627636fb63dd0b7523c466f9" }, { "url": "https://git.kernel.org/stable/c/2cef2588c995722a901368def30befeef9ae55c6" } ], "title": "net/sched: hhf: cap hh_flows_limit at change time", "x_generator": { "engine": "bippy-1.2.0" } } } }