{"id":"CVE-2026-98012","revision":"6f4dfe3e29ca4507b63d22e8171a0206","records":[{"revision":"6f4dfe3e29ca4507b63d22e8171a0206","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98012","aliases":[],"title":"net/sched: sfq: clamp quantum in change path","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: sfq: clamp quantum in change path\n\nsfq_change() accepts any non-negative quantum (only rejects\n(int)ctl->quantum < 0). With a crafted size table qdisc_pkt_len reaches\n~2 GiB, so quantum=1 makes the deficit-refill loop spin ~2^31 times\nunder the qdisc lock (a soft lockup / denial of service).\n\nAdd max(256U, ...) matching fq_codel_change(). Reject quantum > 1<<20\nwith -EINVAL, matching fq_codel_change() and the init clamp.\n\nConditions to recreate the bug:\n  CONFIG_NET_SCH_SFQ=y. Requires CAP_NET_ADMIN (namespace-local via\n  unshare -Urn suffices).\n\n  tc qdisc add dev dummy0 root sfq\n  tc qdisc change dev dummy0 root sfq quantum 1 stab data 32768 size_log 15 cell_log 0","state":0,"publishedAt":"2026-09-25T10:23:35.934+00:00","modifiedAt":"2026-10-19T09:12:17.681+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_sfq.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4919649699c5f4dbae08b8e2ed536fc9d6c3c2aa\",\n                            \"lessThan\": \"4117c528b2de5fdc3e4a7e3626815b616a635cdc\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"548cf048b426729a7a1fa6acd1271c010c9a7380\",\n                            \"lessThan\": \"f82fa6f10d4a69322cad0f7a4aa523ce6292a5a0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c49ac48fac51a6a54efd5963954d02bacf075085\",\n                            \"lessThan\": \"0692ce5a528df450d64e9f819054177e9d91076f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"58ae7465f0e7113d45aa88a66bf2d203c71c195e\",\n                            \"lessThan\": \"e4192bcf83aaab02129644ddf4656fd86e93751f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"82bd38bd5467ece1ee274b493f51326cf5220a5a\",\n                            \"lessThan\": \"f3820dce042a673fcb28cc31c87ee14257e21a17\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e4650d7ae4252f67e997a632adfae0dd74d3a99a\",\n                            \"lessThan\": \"534cd7ecbbc6e8a974f4003a5c1557439c6e0a72\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e4650d7ae4252f67e997a632adfae0dd74d3a99a\",\n                            \"lessThan\": \"e6c1cb728e389354203a72bc77464c222a247aeb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e4650d7ae4252f67e997a632adfae0dd74d3a99a\",\n                            \"lessThan\": \"fb9f88a33c516ea5c0bcd9a22ca288b246b34567\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"843cacb88f42f426973f1ed11c6fb562558efb27\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5.10.239\",\n                            \"lessThan\": \"5.10.271\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.186\",\n                            \"lessThan\": \"5.15.222\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.129\",\n                            \"lessThan\": \"6.1.189\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.76\",\n                            \"lessThan\": \"6.6.158\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.13\",\n                            \"lessThan\": \"6.12.111\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.4.297\",\n                            \"lessThan\": \"5.5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\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_sfq.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.13\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.13\",\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/4117c528b2de5fdc3e4a7e3626815b616a635cdc","https://git.kernel.org/stable/c/f82fa6f10d4a69322cad0f7a4aa523ce6292a5a0","https://git.kernel.org/stable/c/0692ce5a528df450d64e9f819054177e9d91076f","https://git.kernel.org/stable/c/e4192bcf83aaab02129644ddf4656fd86e93751f","https://git.kernel.org/stable/c/f3820dce042a673fcb28cc31c87ee14257e21a17","https://git.kernel.org/stable/c/534cd7ecbbc6e8a974f4003a5c1557439c6e0a72","https://git.kernel.org/stable/c/e6c1cb728e389354203a72bc77464c222a247aeb","https://git.kernel.org/stable/c/fb9f88a33c516ea5c0bcd9a22ca288b246b34567"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98012","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98012","identifiers":["CVE-2026-98012"]},"retained":false,"historicalAffected":[]}],"coverage":[]}