{"id":"CVE-2026-90111","summary":"ip6mr: do not clone dst in ip6mr_cache_report()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nip6mr: do not clone dst in ip6mr_cache_report()\n\nIPv6 input attaches a non-refcounted (NOREF) dst to skbs under RCU.\nWhen an ingress multicast packet misses MFC lookup,\nip6mr_cache_unresolved() places the skb onto the unresolved queue,\nescaping the receive-side RCU grace period.\n\nIf the underlying route is deleted and freed, and the MFC queue is later\nresolved with a wrong parent interface, ip6_mr_forward() invokes\nip6mr_cache_report(..., MRT6MSG_WRONGMIF), which executes\ndst_clone(skb_dst(pkt)) on the freed dst entry, triggering a slab\nuse-after-free.\n\nReport packets queued to mroute6_sk (a raw socket) and netlink\nnotifications do not require an attached dst entry.\n\nFix this by:\n1. Removing dst_clone() in ip6mr_cache_report() and ensuring report skbs\n   do not hold a dst.\n2. Dropping skb_dst before queuing unresolved skbs in\n   ip6mr_cache_unresolved(), matching the fact that multicast\n   forwarding resolves outgoing routes anew via ip6_route_output().","modified":"2026-09-19T03:47:24.401502379Z","published":"2026-09-17T16:06:18.779Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90111.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/235b42b5860189eb8c27c36435ad932cae65a734"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4a674afaae4136c71943aa3e35d433676fd40e8f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90111.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90111"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"67f415dd29063a5906c560051c00e42dcf01a4dd"},{"fixed":"4a674afaae4136c71943aa3e35d433676fd40e8f"},{"fixed":"235b42b5860189eb8c27c36435ad932cae65a734"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90111.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.3.0"},{"fixed":"7.2.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-90111.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}