{"api_version":"1","generated_at":"2026-09-11T09:57:19+00:00","cve":"CVE-2026-80837","urls":{"html":"https://cve.report/CVE-2026-80837","api":"https://cve.report/api/cve/CVE-2026-80837.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-80837","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80837"},"summary":{"title":"netfilter: nf_tables: don't queue packet path object notifications","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: don't queue packet path object notifications\n\nAll file:line references below are against v7.2-rc4 (ac5b0e5651b1). The\ntrace was captured on 7.2.0-rc6-kasan72rc6 (075b74841bd0), where the same\nlines apply.\n\nnft_obj_notify() is exported and reached from the packet path. Its only\nin-tree caller is nft_quota_obj_eval() (net/netfilter/nft_quota.c:68),\nwhich notifies with GFP_ATOMIC while evaluating a rule for a transiting\npacket, holding no mutex.\n\nSince commit 67cc570edaa0 (\"netfilter: nf_tables: coalesce multiple\nnotifications into one skbuff\") that notification is no longer sent\nimmediately. __nft_obj_notify() queues it onto nft_net->notify_list via\nnft_notify_enqueue() (net/netfilter/nf_tables_api.c:1211), which is a bare\nlist_add_tail(). notify_list has no lock of its own\n(include/net/netfilter/nf_tables.h:1951), it is serialised by commit_mutex:\nthe six other enqueue sites all run inside a netlink transaction, and the\ndrain in nft_commit_notify() (net/netfilter/nf_tables_api.c:10746) does\nlist_del() + kfree_skb() from nf_tables_commit() with commit_mutex held.\n\nSending packets through a chain that references a depleted quota object\ntherefore races an unlocked list_add_tail() against list_del() +\nkfree_skb() on another CPU. The WRITE_ONCE(prev->next, new) in __list_add()\nthen stores through an sk_buff that has already been freed:\n\n  BUG: KASAN: slab-use-after-free in __nft_obj_notify+0x2c5/0x2d0\n  Write of size 8 at addr ff110001047183c0 by task poc/76\n  CPU: 0 UID: 1000 PID: 76 Comm: poc Tainted: G  W  7.2.0-rc6-kasan72rc6 #4\n  Call Trace:\n   <IRQ>\n   __nft_obj_notify (include/linux/list.h:164 include/linux/list.h:191\n                     net/netfilter/nf_tables_api.c:1211\n                     net/netfilter/nf_tables_api.c:8743)\n   nft_quota_obj_eval (net/netfilter/nft_quota.c:68)\n   nft_do_chain_inet\n   nf_hook_slow\n   __ip_local_out\n   ip_push_pending_frames\n   udp_send_skb\n   udp_sendmsg\n   __x64_sys_sendto\n\n  Allocated by task 77:\n   __alloc_skb (net/core/skbuff.c:704)\n   __nft_obj_notify (include/net/netlink.h:1055\n                     net/netfilter/nf_tables_api.c:8731)\n   nft_quota_obj_eval (net/netfilter/nft_quota.c:68)\n   nft_do_chain\n\n  Freed by task 79:\n   nf_tables_commit (include/linux/skbuff.h:1332\n                     net/netfilter/nf_tables_api.c:10759\n                     net/netfilter/nf_tables_api.c:11185)\n   nfnetlink_rcv_batch (net/netfilter/nfnetlink.c:574)\n   netlink_unicast\n   netlink_sendmsg\n\n  The buggy address belongs to the cache skbuff_head_cache of size 232\n\nQueueing from the packet path is wrong even leaving the race aside:\nnotify_list is only drained by nft_commit_notify() from nf_tables_commit()\n(:11185), so a notification enqueued outside a transaction is not sent\nuntil some later netlink batch commits, if one ever does.\n\nThe gfp argument that nft_obj_notify() still takes is a leftover of the\npre-67cc570edaa0 behaviour, where this path called nfnetlink_send()\ndirectly. Restore that: split the message construction out into\nnft_obj_notify_alloc() and let each caller decide what to do with the skb.\nnft_obj_notify(), the exported one reached from the packet path, sends it\nstraight away; nf_tables_obj_notify(), which runs under commit_mutex, keeps\nqueueing it, so transaction notifications are still coalesced.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-04 16:18:12","updated_at":"2026-09-04 16:18:12"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/68de7f3a38acab355c24114f77bf00d3094ce4da","name":"https://git.kernel.org/stable/c/68de7f3a38acab355c24114f77bf00d3094ce4da","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e97e2d6d0b150fd78be573f9fdf193f204d9334e","name":"https://git.kernel.org/stable/c/e97e2d6d0b150fd78be573f9fdf193f204d9334e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/df86c0e84025be8b6dd572a20852698927aa666b","name":"https://git.kernel.org/stable/c/df86c0e84025be8b6dd572a20852698927aa666b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7904b94768e983bcb2be34a8d6d1f3450f5b838b","name":"https://git.kernel.org/stable/c/7904b94768e983bcb2be34a8d6d1f3450f5b838b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6fa88d11983c6fe693c13ed7c5b3b75ae9f39de6","name":"https://git.kernel.org/stable/c/6fa88d11983c6fe693c13ed7c5b3b75ae9f39de6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-80837","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80837","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 67cc570edaa02016a8685a06a0ee91f05a6277d9 df86c0e84025be8b6dd572a20852698927aa666b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 67cc570edaa02016a8685a06a0ee91f05a6277d9 6fa88d11983c6fe693c13ed7c5b3b75ae9f39de6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 67cc570edaa02016a8685a06a0ee91f05a6277d9 e97e2d6d0b150fd78be573f9fdf193f204d9334e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 67cc570edaa02016a8685a06a0ee91f05a6277d9 68de7f3a38acab355c24114f77bf00d3094ce4da git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 67cc570edaa02016a8685a06a0ee91f05a6277d9 7904b94768e983bcb2be34a8d6d1f3450f5b838b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.9","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.108 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.49 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.13 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.3 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"80837","cve":"CVE-2026-80837","epss":"0.001680000","percentile":"0.063410000","score_date":"2026-09-07","updated_at":"2026-09-08 00:05:27"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/netfilter/nf_tables_api.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"df86c0e84025be8b6dd572a20852698927aa666b","status":"affected","version":"67cc570edaa02016a8685a06a0ee91f05a6277d9","versionType":"git"},{"lessThan":"6fa88d11983c6fe693c13ed7c5b3b75ae9f39de6","status":"affected","version":"67cc570edaa02016a8685a06a0ee91f05a6277d9","versionType":"git"},{"lessThan":"e97e2d6d0b150fd78be573f9fdf193f204d9334e","status":"affected","version":"67cc570edaa02016a8685a06a0ee91f05a6277d9","versionType":"git"},{"lessThan":"68de7f3a38acab355c24114f77bf00d3094ce4da","status":"affected","version":"67cc570edaa02016a8685a06a0ee91f05a6277d9","versionType":"git"},{"lessThan":"7904b94768e983bcb2be34a8d6d1f3450f5b838b","status":"affected","version":"67cc570edaa02016a8685a06a0ee91f05a6277d9","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/netfilter/nf_tables_api.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.9"},{"lessThan":"5.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.108","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.49","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.13","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.3","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.108","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.49","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.13","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.3","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"5.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: don't queue packet path object notifications\n\nAll file:line references below are against v7.2-rc4 (ac5b0e5651b1). The\ntrace was captured on 7.2.0-rc6-kasan72rc6 (075b74841bd0), where the same\nlines apply.\n\nnft_obj_notify() is exported and reached from the packet path. Its only\nin-tree caller is nft_quota_obj_eval() (net/netfilter/nft_quota.c:68),\nwhich notifies with GFP_ATOMIC while evaluating a rule for a transiting\npacket, holding no mutex.\n\nSince commit 67cc570edaa0 (\"netfilter: nf_tables: coalesce multiple\nnotifications into one skbuff\") that notification is no longer sent\nimmediately. __nft_obj_notify() queues it onto nft_net->notify_list via\nnft_notify_enqueue() (net/netfilter/nf_tables_api.c:1211), which is a bare\nlist_add_tail(). notify_list has no lock of its own\n(include/net/netfilter/nf_tables.h:1951), it is serialised by commit_mutex:\nthe six other enqueue sites all run inside a netlink transaction, and the\ndrain in nft_commit_notify() (net/netfilter/nf_tables_api.c:10746) does\nlist_del() + kfree_skb() from nf_tables_commit() with commit_mutex held.\n\nSending packets through a chain that references a depleted quota object\ntherefore races an unlocked list_add_tail() against list_del() +\nkfree_skb() on another CPU. The WRITE_ONCE(prev->next, new) in __list_add()\nthen stores through an sk_buff that has already been freed:\n\n  BUG: KASAN: slab-use-after-free in __nft_obj_notify+0x2c5/0x2d0\n  Write of size 8 at addr ff110001047183c0 by task poc/76\n  CPU: 0 UID: 1000 PID: 76 Comm: poc Tainted: G  W  7.2.0-rc6-kasan72rc6 #4\n  Call Trace:\n   <IRQ>\n   __nft_obj_notify (include/linux/list.h:164 include/linux/list.h:191\n                     net/netfilter/nf_tables_api.c:1211\n                     net/netfilter/nf_tables_api.c:8743)\n   nft_quota_obj_eval (net/netfilter/nft_quota.c:68)\n   nft_do_chain_inet\n   nf_hook_slow\n   __ip_local_out\n   ip_push_pending_frames\n   udp_send_skb\n   udp_sendmsg\n   __x64_sys_sendto\n\n  Allocated by task 77:\n   __alloc_skb (net/core/skbuff.c:704)\n   __nft_obj_notify (include/net/netlink.h:1055\n                     net/netfilter/nf_tables_api.c:8731)\n   nft_quota_obj_eval (net/netfilter/nft_quota.c:68)\n   nft_do_chain\n\n  Freed by task 79:\n   nf_tables_commit (include/linux/skbuff.h:1332\n                     net/netfilter/nf_tables_api.c:10759\n                     net/netfilter/nf_tables_api.c:11185)\n   nfnetlink_rcv_batch (net/netfilter/nfnetlink.c:574)\n   netlink_unicast\n   netlink_sendmsg\n\n  The buggy address belongs to the cache skbuff_head_cache of size 232\n\nQueueing from the packet path is wrong even leaving the race aside:\nnotify_list is only drained by nft_commit_notify() from nf_tables_commit()\n(:11185), so a notification enqueued outside a transaction is not sent\nuntil some later netlink batch commits, if one ever does.\n\nThe gfp argument that nft_obj_notify() still takes is a leftover of the\npre-67cc570edaa0 behaviour, where this path called nfnetlink_send()\ndirectly. Restore that: split the message construction out into\nnft_obj_notify_alloc() and let each caller decide what to do with the skb.\nnft_obj_notify(), the exported one reached from the packet path, sends it\nstraight away; nf_tables_obj_notify(), which runs under commit_mutex, keeps\nqueueing it, so transaction notifications are still coalesced."}],"providerMetadata":{"dateUpdated":"2026-09-04T15:54:47.179Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/df86c0e84025be8b6dd572a20852698927aa666b"},{"url":"https://git.kernel.org/stable/c/6fa88d11983c6fe693c13ed7c5b3b75ae9f39de6"},{"url":"https://git.kernel.org/stable/c/e97e2d6d0b150fd78be573f9fdf193f204d9334e"},{"url":"https://git.kernel.org/stable/c/68de7f3a38acab355c24114f77bf00d3094ce4da"},{"url":"https://git.kernel.org/stable/c/7904b94768e983bcb2be34a8d6d1f3450f5b838b"}],"title":"netfilter: nf_tables: don't queue packet path object notifications","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-80837","datePublished":"2026-09-04T15:54:47.179Z","dateReserved":"2026-08-26T14:34:25.796Z","dateUpdated":"2026-09-04T15:54:47.179Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-04 16:18:12","lastModifiedDate":"2026-09-04 16:18:12","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"80837","Ordinal":"1","Title":"netfilter: nf_tables: don't queue packet path object notificatio","CVE":"CVE-2026-80837","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"80837","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_tables: don't queue packet path object notifications\n\nAll file:line references below are against v7.2-rc4 (ac5b0e5651b1). The\ntrace was captured on 7.2.0-rc6-kasan72rc6 (075b74841bd0), where the same\nlines apply.\n\nnft_obj_notify() is exported and reached from the packet path. Its only\nin-tree caller is nft_quota_obj_eval() (net/netfilter/nft_quota.c:68),\nwhich notifies with GFP_ATOMIC while evaluating a rule for a transiting\npacket, holding no mutex.\n\nSince commit 67cc570edaa0 (\"netfilter: nf_tables: coalesce multiple\nnotifications into one skbuff\") that notification is no longer sent\nimmediately. __nft_obj_notify() queues it onto nft_net->notify_list via\nnft_notify_enqueue() (net/netfilter/nf_tables_api.c:1211), which is a bare\nlist_add_tail(). notify_list has no lock of its own\n(include/net/netfilter/nf_tables.h:1951), it is serialised by commit_mutex:\nthe six other enqueue sites all run inside a netlink transaction, and the\ndrain in nft_commit_notify() (net/netfilter/nf_tables_api.c:10746) does\nlist_del() + kfree_skb() from nf_tables_commit() with commit_mutex held.\n\nSending packets through a chain that references a depleted quota object\ntherefore races an unlocked list_add_tail() against list_del() +\nkfree_skb() on another CPU. The WRITE_ONCE(prev->next, new) in __list_add()\nthen stores through an sk_buff that has already been freed:\n\n  BUG: KASAN: slab-use-after-free in __nft_obj_notify+0x2c5/0x2d0\n  Write of size 8 at addr ff110001047183c0 by task poc/76\n  CPU: 0 UID: 1000 PID: 76 Comm: poc Tainted: G  W  7.2.0-rc6-kasan72rc6 #4\n  Call Trace:\n   <IRQ>\n   __nft_obj_notify (include/linux/list.h:164 include/linux/list.h:191\n                     net/netfilter/nf_tables_api.c:1211\n                     net/netfilter/nf_tables_api.c:8743)\n   nft_quota_obj_eval (net/netfilter/nft_quota.c:68)\n   nft_do_chain_inet\n   nf_hook_slow\n   __ip_local_out\n   ip_push_pending_frames\n   udp_send_skb\n   udp_sendmsg\n   __x64_sys_sendto\n\n  Allocated by task 77:\n   __alloc_skb (net/core/skbuff.c:704)\n   __nft_obj_notify (include/net/netlink.h:1055\n                     net/netfilter/nf_tables_api.c:8731)\n   nft_quota_obj_eval (net/netfilter/nft_quota.c:68)\n   nft_do_chain\n\n  Freed by task 79:\n   nf_tables_commit (include/linux/skbuff.h:1332\n                     net/netfilter/nf_tables_api.c:10759\n                     net/netfilter/nf_tables_api.c:11185)\n   nfnetlink_rcv_batch (net/netfilter/nfnetlink.c:574)\n   netlink_unicast\n   netlink_sendmsg\n\n  The buggy address belongs to the cache skbuff_head_cache of size 232\n\nQueueing from the packet path is wrong even leaving the race aside:\nnotify_list is only drained by nft_commit_notify() from nf_tables_commit()\n(:11185), so a notification enqueued outside a transaction is not sent\nuntil some later netlink batch commits, if one ever does.\n\nThe gfp argument that nft_obj_notify() still takes is a leftover of the\npre-67cc570edaa0 behaviour, where this path called nfnetlink_send()\ndirectly. Restore that: split the message construction out into\nnft_obj_notify_alloc() and let each caller decide what to do with the skb.\nnft_obj_notify(), the exported one reached from the packet path, sends it\nstraight away; nf_tables_obj_notify(), which runs under commit_mutex, keeps\nqueueing it, so transaction notifications are still coalesced.","Type":"Description","Title":"netfilter: nf_tables: don't queue packet path object notificatio"}]}}}