{"id":"CVE-2026-98010","summary":"net/sched: drr: clamp quantum in change class","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: drr: clamp quantum in change class\n\ndrr_change_class() rejects explicit quantum==0 but falls back to\npsched_mtu() with no floor. With a crafted size table qdisc_pkt_len\nreaches ~2 GiB, so quantum=1 (or a zero psched_mtu on a headerless\ndevice) makes the deficit-refill loop spin under the qdisc lock.\n\nAdd clamp_t(u32, quantum, 256, 1\u003c\u003c20) after the zero reject and on the\nfallback path. The explicit-zero reject is preserved.\n\nConditions to recreate the bug:\n  CONFIG_NET_SCH_DRR=y. Requires CAP_NET_ADMIN (namespace-local via\n  unshare -Urn suffices).\n\n  tc qdisc add dev dummy0 root drr\n  tc class add dev dummy0 parent 1: classid 1:1 drr quantum 1","modified":"2026-09-26T03:48:31.070619435Z","published":"2026-09-25T10:23:34.738Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98010.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8382abec0f1568d0a5590d75a3df92f23fcf5196"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8f756ae1c87414ce9cc21b30e6e4c036d6e9e80b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d43cded350fe1218493ad3d37a276aff14108ae6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dc8b374214ef5bba4882bbd95b361e42555cfc0d"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98010.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98010"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"13d2a1d2b032de08d7dcab6a1edcd47802681f96"},{"fixed":"dc8b374214ef5bba4882bbd95b361e42555cfc0d"},{"fixed":"d43cded350fe1218493ad3d37a276aff14108ae6"},{"fixed":"8f756ae1c87414ce9cc21b30e6e4c036d6e9e80b"},{"fixed":"8382abec0f1568d0a5590d75a3df92f23fcf5196"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98010.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.29"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.53"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98010.json"}}],"schema_version":"1.9.0"}