{"id":"AZL-100580","summary":"CVE-2026-89564 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nip: orphan prefetched skbs before multicast forwarding\n\nIPv4 and IPv6 input preserve an skb-\u003esk association installed by\nbpf_sk_assign() so that local delivery can use the selected socket under\nRCU. Both address families can also prefetch a socket in UDP early demux.\nIn both paths (BPF and UDP early demux) a reference is not guaranteed to\nbe held on the socket.\n\nWhen a multicast packet is not locally deliverable, IPv6 hands the\noriginal skb to ip6_mr_input(). IPv4's ip_mr_input() similarly keeps the\noriginal skb when local delivery is not needed. Either path can put the\nskb on an unresolved multicast route queue or forward it after the\nreceive-side RCU section ends.\n\nAfter the prefetched socket is destroyed, a later skb free invokes\nsock_pfree() and dereferences the stale skb-\u003esk. Orphan the skb before\neach non-local multicast forwarding path. Local delivery retains the\noriginal skb; the existing skb_clone() calls provide multicast forwarding\nwith a socket-free clone.","modified":"2026-09-13T06:06:36Z","published":"2026-09-11T20:19:40Z","upstream":["CVE-2026-89564"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89564"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-100580.json"}}],"schema_version":"1.9.0"}