{"id":"CVE-2026-64423","summary":"ipv4: igmp: remove multicast group from hash table on device destruction","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: igmp: remove multicast group from hash table on device destruction\n\nWhen a device is destroyed under RTNL, ip_mc_destroy_dev() iterates through\nthe multicast list and calls ip_ma_put() on each membership, scheduling\nthem for RCU reclamation. However, they are not unlinked from the device's\nmulticast hash table (mc_hash).\n\nSince the device remains published in dev-\u003eip_ptr until after\nip_mc_destroy_dev() completes, concurrent RCU readers traversing mc_hash\ncan still locate and access the multicast group after its refcount is\ndecremented. If the RCU callback runs and frees the group while a reader is\naccessing it, a use-after-free occurs.\n\nFix this by unlinking the multicast group from mc_hash using\nip_mc_hash_remove() before scheduling it for reclamation.\n\nBUG: KASAN: slab-use-after-free in ip_check_mc_rcu+0x149/0x3f0\nRead of size 4 at addr ffff888009bf1408 by task mausezahn/2276\n\nCall Trace:\n \u003cIRQ\u003e\n dump_stack_lvl+0x67/0x90\n print_report+0x175/0x7c0\n kasan_report+0x147/0x180\n ip_check_mc_rcu+0x149/0x3f0\n udp_v4_early_demux+0x36d/0x12d0\n ip_rcv_finish_core+0xb8b/0x1390\n ip_rcv_finish+0x54/0x120\n NF_HOOK+0x213/0x2b0\n __netif_receive_skb+0x126/0x340\n process_backlog+0x4f2/0xf00\n __napi_poll+0x92/0x2c0\n net_rx_action+0x583/0xc60\n handle_softirqs+0x236/0x7f0\n do_softirq+0x57/0x80\n \u003c/IRQ\u003e\n\nAllocated by task 2239:\n kasan_save_track+0x3e/0x80\n __kasan_kmalloc+0x72/0x90\n ____ip_mc_inc_group+0x31a/0xa40\n __ip_mc_join_group+0x334/0x3f0\n do_ip_setsockopt+0x16fa/0x2010\n ip_setsockopt+0x3f/0x90\n do_sock_setsockopt+0x1ad/0x300\n\nFreed by task 0:\n kasan_save_track+0x3e/0x80\n kasan_save_free_info+0x40/0x50\n __kasan_slab_free+0x3a/0x60\n __rcu_free_sheaf_prepare+0xd4/0x220\n rcu_free_sheaf+0x36/0x190\n rcu_core+0x8d9/0x12f0\n handle_softirqs+0x236/0x7f0","modified":"2026-09-30T18:26:48.601825027Z","published":"2026-07-25T08:51:01.485Z","related":["SUSE-SU-2026:23477-1","SUSE-SU-2026:23481-1","SUSE-SU-2026:23528-1","SUSE-SU-2026:23529-1","SUSE-SU-2026:23672-1","SUSE-SU-2026:23673-1","SUSE-SU-2026:23674-1","SUSE-SU-2026:23675-1","SUSE-SU-2026:23676-1","SUSE-SU-2026:23677-1","SUSE-SU-2026:23678-1","SUSE-SU-2026:23679-1","SUSE-SU-2026:23680-1","SUSE-SU-2026:23681-1","SUSE-SU-2026:23682-1","SUSE-SU-2026:23683-1","SUSE-SU-2026:23684-1","SUSE-SU-2026:23685-1","SUSE-SU-2026:23686-1","SUSE-SU-2026:23687-1","SUSE-SU-2026:23747-1","SUSE-SU-2026:23748-1","SUSE-SU-2026:23749-1","SUSE-SU-2026:23750-1","SUSE-SU-2026:23751-1","SUSE-SU-2026:23752-1","SUSE-SU-2026:23753-1","SUSE-SU-2026:23754-1","SUSE-SU-2026:23755-1","SUSE-SU-2026:23756-1","SUSE-SU-2026:23757-1","SUSE-SU-2026:23758-1","SUSE-SU-2026:23759-1","SUSE-SU-2026:23760-1","SUSE-SU-2026:23761-1","SUSE-SU-2026:23762-1","SUSE-SU-2026:23763-1","SUSE-SU-2026:23764-1","SUSE-SU-2026:23766-1","SUSE-SU-2026:23767-1","SUSE-SU-2026:23768-1","SUSE-SU-2026:23769-1","SUSE-SU-2026:23770-1","SUSE-SU-2026:23771-1","SUSE-SU-2026:23772-1","SUSE-SU-2026:23773-1","SUSE-SU-2026:23774-1","SUSE-SU-2026:23775-1","SUSE-SU-2026:23776-1","SUSE-SU-2026:23777-1","SUSE-SU-2026:23778-1","SUSE-SU-2026:23779-1","SUSE-SU-2026:23780-1","SUSE-SU-2026:23781-1","SUSE-SU-2026:23789-1","SUSE-SU-2026:23790-1","SUSE-SU-2026:23791-1","SUSE-SU-2026:23797-1","SUSE-SU-2026:23798-1","SUSE-SU-2026:23799-1","SUSE-SU-2026:23801-1","SUSE-SU-2026:23803-1","SUSE-SU-2026:23804-1","SUSE-SU-2026:23805-1","SUSE-SU-2026:23806-1","SUSE-SU-2026:23807-1","SUSE-SU-2026:23808-1","SUSE-SU-2026:23809-1","SUSE-SU-2026:23810-1","SUSE-SU-2026:23811-1","SUSE-SU-2026:23812-1","SUSE-SU-2026:23813-1","SUSE-SU-2026:23814-1","SUSE-SU-2026:23815-1","SUSE-SU-2026:23816-1","SUSE-SU-2026:23817-1","SUSE-SU-2026:23818-1","SUSE-SU-2026:23819-1","SUSE-SU-2026:23820-1","SUSE-SU-2026:23821-1","SUSE-SU-2026:23822-1","SUSE-SU-2026:23823-1","SUSE-SU-2026:23824-1","SUSE-SU-2026:23825-1","SUSE-SU-2026:23826-1","SUSE-SU-2026:23827-1","SUSE-SU-2026:23828-1","SUSE-SU-2026:23832-1","SUSE-SU-2026:23833-1","SUSE-SU-2026:23834-1","SUSE-SU-2026:23835-1","SUSE-SU-2026:23836-1","SUSE-SU-2026:23837-1","SUSE-SU-2026:23838-1","SUSE-SU-2026:23839-1","SUSE-SU-2026:23881-1","SUSE-SU-2026:23887-1","SUSE-SU-2026:23897-1","SUSE-SU-2026:23902-1","SUSE-SU-2026:4120-1","SUSE-SU-2026:4168-1","SUSE-SU-2026:4170-1","SUSE-SU-2026:4172-1","SUSE-SU-2026:4183-1","SUSE-SU-2026:4185-1","SUSE-SU-2026:4192-1","SUSE-SU-2026:4193-1","SUSE-SU-2026:4231-1","SUSE-SU-2026:4244-1","SUSE-SU-2026:4254-1","SUSE-SU-2026:4255-1","SUSE-SU-2026:4256-1","SUSE-SU-2026:4258-1","SUSE-SU-2026:4259-1","SUSE-SU-2026:4279-1","SUSE-SU-2026:4282-1","SUSE-SU-2026:4284-1","SUSE-SU-2026:4310-1","SUSE-SU-2026:4315-1","SUSE-SU-2026:4347-1","SUSE-SU-2026:4356-1","SUSE-SU-2026:4357-1","SUSE-SU-2026:4359-1","SUSE-SU-2026:4369-1","SUSE-SU-2026:4383-1","openSUSE-SU-2026:11476-1","openSUSE-SU-2026:21910-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64423.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2ca18df1c2611f70eb3eb487e02ae85eb703b284"},{"type":"WEB","url":"https://git.kernel.org/stable/c/412ba7def06ffe974ba9a1d862b022362c54ffa5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5f42729d74bd6c61306d864423290d92962de4e1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/76d030ac95e17f91d69a595f17ebc5979700cf9a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7993211bde166471dffac074dc965489f86531f8"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8820b530cb2388503d7418228d03ba074bf7a03e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f91883031e5a62877a29ce139442973cbea769f1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64423.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64423"},{"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":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7"},{"fixed":"412ba7def06ffe974ba9a1d862b022362c54ffa5"},{"fixed":"c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9"},{"fixed":"5f42729d74bd6c61306d864423290d92962de4e1"},{"fixed":"76d030ac95e17f91d69a595f17ebc5979700cf9a"},{"fixed":"8820b530cb2388503d7418228d03ba074bf7a03e"},{"fixed":"2ca18df1c2611f70eb3eb487e02ae85eb703b284"},{"fixed":"f91883031e5a62877a29ce139442973cbea769f1"},{"fixed":"7993211bde166471dffac074dc965489f86531f8"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64423.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.11.0"},{"fixed":"5.10.261"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.96"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.39"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64423.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"}]}