{"id":"AZL-93957","summary":"CVE-2026-64530 affecting package kernel for versions less than 6.6.145.2-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_api: Handle TC_ACT_CONSUMED in tcf_qevent_handle\n\ntcf_classify() can return TC_ACT_CONSUMED while the skb is held by the\ndefragmentation engine (e.g. act_ct on out-of-order fragments). When\nthat happens the skb is no longer owned by the caller and must not be\ntouched again.\n\ntcf_qevent_handle() did not handle TC_ACT_CONSUMED: it fell through the\nswitch and returned the skb to the caller as if classification had\npassed. The only qdisc that wires up qevents today is RED, via three call sites\n(qe_mark on RED_PROB_MARK/HARD_MARK, qe_early_drop on congestion_drop)\nred_enqueue() was continuing to operate on an skb it no longer owns  in this\ncase -- enqueueing it, dropping it, or updating statistics. Resulting in a UAF.\n\n  tc qdisc add dev eth0 root handle 1: red ... qevent early_drop block 10\n  tc filter add block 10 ... action ct\n\n  (with ct defrag enabled and traffic that produces out-of-order\n  fragments, e.g. a fragmented UDP stream)\n\nHandle TC_ACT_CONSUMED in tcf_qevent_handle() the same way the ingress\nand egress fast paths do: treat it as stolen and return NULL without\ntouching the skb. Unlike the TC_ACT_STOLEN case, the skb must not be\ndropped/freed here, as it is no longer owned by us.","modified":"2026-08-28T17:46:29.861230152Z","published":"2026-07-26T07:16:41Z","upstream":["CVE-2026-64530"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64530"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.145.2-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-93957.json"}}],"schema_version":"1.9.0"}