{"id":"AZL-64764","summary":"CVE-2025-38193 affecting package kernel for versions less than 6.6.96.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet_sched: sch_sfq: reject invalid perturb period\n\nGerrard Tai reported that SFQ perturb_period has no range check yet,\nand this can be used to trigger a race condition fixed in a separate patch.\n\nWe want to make sure ctl-\u003eperturb_period * HZ will not overflow\nand is positive.\n\n\ntc qd add dev lo root sfq perturb -10   # negative value : error\nError: sch_sfq: invalid perturb period.\n\ntc qd add dev lo root sfq perturb 1000000000 # too big : error\nError: sch_sfq: invalid perturb period.\n\ntc qd add dev lo root sfq perturb 2000000 # acceptable value\ntc -s -d qd sh dev lo\nqdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec\n Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)\n backlog 0b 0p requeues 0","modified":"2026-04-01T05:20:23.521503Z","published":"2025-07-04T14:15:26Z","upstream":["CVE-2025-38193"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-38193"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.96.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-64764.json"}}],"schema_version":"1.7.5"}