{"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":"2026-10-06T08:45:07.215Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-10-06T08:45:07.215Z"},"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-rc4","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-rc4"}]}]}],"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"}}}}