{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-80837", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-26T14:34:25.796Z", "datePublished": "2026-09-04T15:54:47.179Z", "dateUpdated": "2026-10-19T08:44:29.494Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:44:29.494Z" }, "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 \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." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_tables_api.c" ], "versions": [ { "version": "67cc570edaa02016a8685a06a0ee91f05a6277d9", "lessThan": "6989f298103f575a768a85e4b19d2384709237f8", "status": "affected", "versionType": "git" }, { "version": "67cc570edaa02016a8685a06a0ee91f05a6277d9", "lessThan": "df86c0e84025be8b6dd572a20852698927aa666b", "status": "affected", "versionType": "git" }, { "version": "67cc570edaa02016a8685a06a0ee91f05a6277d9", "lessThan": "6fa88d11983c6fe693c13ed7c5b3b75ae9f39de6", "status": "affected", "versionType": "git" }, { "version": "67cc570edaa02016a8685a06a0ee91f05a6277d9", "lessThan": "e97e2d6d0b150fd78be573f9fdf193f204d9334e", "status": "affected", "versionType": "git" }, { "version": "67cc570edaa02016a8685a06a0ee91f05a6277d9", "lessThan": "68de7f3a38acab355c24114f77bf00d3094ce4da", "status": "affected", "versionType": "git" }, { "version": "67cc570edaa02016a8685a06a0ee91f05a6277d9", "lessThan": "7904b94768e983bcb2be34a8d6d1f3450f5b838b", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_tables_api.c" ], "versions": [ { "version": "5.9", "status": "affected" }, { "version": "0", "lessThan": "5.9", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.108", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.49", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.13", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.3", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.9", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.9", "versionEndExcluding": "6.12.108" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.9", "versionEndExcluding": "6.18.49" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.9", "versionEndExcluding": "7.1.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.9", "versionEndExcluding": "7.2.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.9", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6989f298103f575a768a85e4b19d2384709237f8" }, { "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" } } } }