{"id":"CVE-2026-98012","title":"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)","summary":"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_le…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 82bd38bd5467ece1ee274b493f51326cf5220a5a < f3820dce042a673fcb28cc31c87ee14257e21a17","Linux >= e4650d7ae4252f67e997a632adfae0dd74d3a99a < 534cd7ecbbc6e8a974f4003a5c1557439c6e0a72","Linux >= e4650d7ae4252f67e997a632adfae0dd74d3a99a < e6c1cb728e389354203a72bc77464c222a247aeb","Linux >= e4650d7ae4252f67e997a632adfae0dd74d3a99a < fb9f88a33c516ea5c0bcd9a22ca288b246b34567","Linux 843cacb88f42f426973f1ed11c6fb562558efb27","Linux 4919649699c5f4dbae08b8e2ed536fc9d6c3c2aa","Linux 548cf048b426729a7a1fa6acd1271c010c9a7380","Linux c49ac48fac51a6a54efd5963954d02bacf075085","Linux 58ae7465f0e7113d45aa88a66bf2d203c71c195e","Linux >= 6.12.13 < 6.12.111","Linux >= 5.4.297 < 5.5","Linux >= 5.10.239 < 5.11","Linux >= 5.15.186 < 5.16","Linux >= 6.1.129 < 6.2","Linux >= 6.6.76 < 6.7","Linux 6.13"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T11:17:29.537","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98012","references":[{"url":"https://git.kernel.org/stable/c/534cd7ecbbc6e8a974f4003a5c1557439c6e0a72","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e6c1cb728e389354203a72bc77464c222a247aeb","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f3820dce042a673fcb28cc31c87ee14257e21a17","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fb9f88a33c516ea5c0bcd9a22ca288b246b34567","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-25T11:06:38.858Z","slug":"CVE-2026-98012","body":"## Overview\n\nIn 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\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}