{"id":"CVE-2026-98013","summary":"net/sched: fq_pie: clamp quantum in change path","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: fq_pie: clamp quantum in change path\n\nfq_pie_change() accepts any quantum value from userspace, including 1.\nWith a crafted size table qdisc_pkt_len reaches ~2 GiB, so quantum=1\nmakes the deficit-refill loop spin ~2^31 times under the qdisc lock\n(a soft lockup / denial of service).\n\nAdd max(256U, ...) matching fq_codel_change().\n\nConditions to recreate the bug:\n  CONFIG_NET_SCH_FQ_PIE=y. Requires CAP_NET_ADMIN (namespace-local via\n  unshare -Urn suffices).\n\n  tc qdisc add dev dummy0 root fq_pie\n  tc qdisc change dev dummy0 root fq_pie quantum 1 stab data 32768 size_log 15 cell_log 0","modified":"2026-09-26T03:48:31.558093711Z","published":"2026-09-25T10:23:36.527Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98013.json","cna_assigner":"Linux"},"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/4864f58c53eb47257d55e01f47d4a9f355f7f970"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6655b56e2801008566c594ef231f6c7b3f716c61"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c11e3a39807eb5a200445ae9082843ab86800415"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f90fe65b977e7aa9eb302230a09eb18f8c32ceaa"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98013.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98013"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ec97ecf1ebe485a17cd8395a5f35e6b80b57665a"},{"fixed":"f90fe65b977e7aa9eb302230a09eb18f8c32ceaa"},{"fixed":"c11e3a39807eb5a200445ae9082843ab86800415"},{"fixed":"6655b56e2801008566c594ef231f6c7b3f716c61"},{"fixed":"4864f58c53eb47257d55e01f47d4a9f355f7f970"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98013.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.6.0"},{"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-2026-98013.json"}}],"schema_version":"1.9.0"}