{"id":"CVE-2026-64423","state":"PUBLISHED","title":"ipv4: igmp: remove multicast group from hash table on device destruction","description":"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->ip_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 <IRQ>\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 </IRQ>\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","publishedAt":"2026-07-25T08:51:01.485Z","updatedAt":"2026-10-19T20:38:28.280Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"412ba7def06ffe974ba9a1d862b022362c54ffa5","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"5f42729d74bd6c61306d864423290d92962de4e1","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"76d030ac95e17f91d69a595f17ebc5979700cf9a","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"8820b530cb2388503d7418228d03ba074bf7a03e","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"2ca18df1c2611f70eb3eb487e02ae85eb703b284","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"f91883031e5a62877a29ce139442973cbea769f1","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"7993211bde166471dffac074dc965489f86531f8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/igmp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.11","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/igmp.c"]}],"references":["https://git.kernel.org/stable/c/412ba7def06ffe974ba9a1d862b022362c54ffa5","https://git.kernel.org/stable/c/c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9","https://git.kernel.org/stable/c/5f42729d74bd6c61306d864423290d92962de4e1","https://git.kernel.org/stable/c/76d030ac95e17f91d69a595f17ebc5979700cf9a","https://git.kernel.org/stable/c/8820b530cb2388503d7418228d03ba074bf7a03e","https://git.kernel.org/stable/c/2ca18df1c2611f70eb3eb487e02ae85eb703b284","https://git.kernel.org/stable/c/f91883031e5a62877a29ce139442973cbea769f1","https://git.kernel.org/stable/c/7993211bde166471dffac074dc965489f86531f8","https://cert-portal.siemens.com/productcert/html/ssa-019113.html","https://cert-portal.siemens.com/productcert/html/ssa-457936.html"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64423.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64423","state":"PUBLISHED","datePublished":"2026-07-25T08:51:01.485Z","dateUpdated":"2026-10-19T20:38:28.280Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.787Z"},"containers":{"cna":{"title":"ipv4: igmp: remove multicast group from hash table on device destruction","descriptions":[{"lang":"en","value":"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->ip_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 <IRQ>\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 </IRQ>\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"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"412ba7def06ffe974ba9a1d862b022362c54ffa5","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"5f42729d74bd6c61306d864423290d92962de4e1","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"76d030ac95e17f91d69a595f17ebc5979700cf9a","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"8820b530cb2388503d7418228d03ba074bf7a03e","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"2ca18df1c2611f70eb3eb487e02ae85eb703b284","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"f91883031e5a62877a29ce139442973cbea769f1","versionType":"git"},{"version":"e9897071350bd9d94a56b5b6f79c85b1a98fc7e7","status":"affected","lessThan":"7993211bde166471dffac074dc965489f86531f8","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/igmp.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.11","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.96","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.39","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.4","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/igmp.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/412ba7def06ffe974ba9a1d862b022362c54ffa5"},{"url":"https://git.kernel.org/stable/c/c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9"},{"url":"https://git.kernel.org/stable/c/5f42729d74bd6c61306d864423290d92962de4e1"},{"url":"https://git.kernel.org/stable/c/76d030ac95e17f91d69a595f17ebc5979700cf9a"},{"url":"https://git.kernel.org/stable/c/8820b530cb2388503d7418228d03ba074bf7a03e"},{"url":"https://git.kernel.org/stable/c/2ca18df1c2611f70eb3eb487e02ae85eb703b284"},{"url":"https://git.kernel.org/stable/c/f91883031e5a62877a29ce139442973cbea769f1"},{"url":"https://git.kernel.org/stable/c/7993211bde166471dffac074dc965489f86531f8"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - An end-to-end attacker-controlled trigger requires local socket and netlink operations to create multicast memberships and concurrently destroy IPv4 device state; received multicast packets alone cannot initiate the necessary teardown. These operations are reachable inside an attacker-created user and network namespace.\nAC:L - The attacker can populate mc_hash, generate continuous multicast traffic, and repeatedly tear down IPv4 state, controlling both sides of the race. No victim-dependent timing or secret state is required.\nPR:L - Device teardown or invalid-MTU configuration requires CAP_NET_ADMIN in the target network namespace, while multicast joins and UDP sends are unprivileged. An ordinary user can obtain this namespace-scoped capability through unprivileged user and network namespaces.\nUI:N - Exploitation requires no action by another user once the attacker can execute locally and create the required namespace and traffic.\nS:U - The vulnerable code and resulting host-kernel compromise remain within the same security authority; this is conventional kernel privilege escalation rather than a guest-to-host escape.\nC:H - The stale kmalloc-256 ip_mc_list entry exposes reuse-controlled fields and pointers to kernel reads, making kernel-memory disclosure and broader read primitives plausible.\nI:H - Reallocation permits attacker-influenced object contents to drive spinlock writes and pointer traversal on freed memory, making heap corruption and control-flow hijacking defensible.\nA:H - The confirmed slab use-after-free can dereference corrupted hash pointers or operate on an invalid spinlock, causing a kernel oops, panic, general-protection fault, or hang."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:55:23.253Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.11","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.11","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.11","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.11","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.11","versionEndExcluding":"6.12.96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.11","versionEndExcluding":"6.18.39"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.11","versionEndExcluding":"7.1.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.11","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:23:48.509Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64423","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:40:31.437029Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:38:28.280Z"}}]}}}