{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-93288", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-17T16:02:15.099Z", "datePublished": "2026-09-24T16:02:12.144Z", "dateUpdated": "2026-10-03T10:57:14.695Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-03T10:57:14.695Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state\n\nsashiko reports: \"nfnl_log_net_exit() calls nf_log_unset(), which\nclears the logger pointer without an RCU grace period. Immediately after,\nops_free_list() frees the per-net state while concurrent packets might\nstill be executing nf_log_packet() under rcu_read_lock().\"\n\nClear the pointer via .pre_exit to make sure rcu readers have completed\nbefore pernet storage is free'd. The change in nf_log_syslog.c is only\ndone for consistency: it doesn't use pernet data." } ], "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 - The UAF is in nfnl_log_net_exit() (unset moved to nfnl_log_net_pre_exit): cleanup_net() frees nfnl_log_net via ops_free_list() while nf_log_packet()→nfulnl_log_packet() still uses nfnl_log_pernet(). Setup is local NETLINK_NETFILTER nfulnl_recv_config (NFULNL_CFG_CMD_PF_BIND); no remote protocol message carries the bug.\nAC:L - The attacker PF_BINDs nfulnl_logger through nfulnl_recv_config, generates packets that enter nf_log_packet() (conntrack nf_l4proto_log_invalid() while those hooks still exist, or NFLOG), and drops the netns so cleanup_net() races nfnl_log_net_exit()/ops_free_list() against that reader; both sides are attacker-controlled.\nPR:L - nfnetlink_rcv() requires CAP_NET_ADMIN via netlink_net_capable() in sock_net(skb->sk)->user_ns before nfulnl_recv_config can bind the logger; an unprivileged user obtains that capability in a user+net namespace (unshare -Urn).\nUI:N - The attacker issues nfulnl_recv_config, injects the logged packets, and destroys their own netns; no victim mount, file open, or other interaction is required.\nS:U - The slab UAF of struct nfnl_log_net inside nfulnl_log_packet()/instance_lookup_get_rcu() is host-kernel memory corruption in the same kernel authority, not a VM escape or IOMMU/DMA bypass.\nC:H - After ops_free_list() kfree()s the per-net object, nfulnl_log_packet() still calls nfnl_log_pernet() and instance_lookup_get_rcu() walks the freed instance_table hlist, a slab UAF that can be reclaimed for arbitrary kernel reads.\nI:H - Use-after-free of nfnl_log_net's instance_table and the resulting nfulnl_instance pointer chase (hlist, inst->lock, inst->skb) is a heap UAF write primitive that can hijack control flow.\nA:H - instance_lookup_get_rcu()/nfulnl_log_packet() dereferencing the freed nfnl_log_net can oops or panic the kernel even when the UAF is not turned into a full exploit." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/netfilter/nf_log_syslog.c", "net/netfilter/nfnetlink_log.c" ], "versions": [ { "version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee", "lessThan": "ba2e246aa294f9acd86194ea87fb6834ed0a37ac", "status": "affected", "versionType": "git" }, { "version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee", "lessThan": "5570d6c8b320dbcc602617ee08c27ce752fed65a", "status": "affected", "versionType": "git" }, { "version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee", "lessThan": "3b9aa62d78ce80de47af2db472ff452398755213", "status": "affected", "versionType": "git" }, { "version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee", "lessThan": "f4461654374576e9d5d0245fd534c46ad8509051", "status": "affected", "versionType": "git" }, { "version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee", "lessThan": "dc20050b6b12ca58066715d088e1a537535d938d", "status": "affected", "versionType": "git" }, { "version": "c83fa19603bdaeef17b815713dbbe3230c8a34ee", "lessThan": "33d1469b0124cc0baaea7a2032123b77a81e0940", "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_log_syslog.c", "net/netfilter/nfnetlink_log.c" ], "versions": [ { "version": "4.12", "status": "affected" }, { "version": "0", "lessThan": "4.12", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.222", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.189", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.158", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.111", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.53", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "4.12", "versionEndExcluding": "5.15.222" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.1.189" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.6.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.12.111" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "6.18.53" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ba2e246aa294f9acd86194ea87fb6834ed0a37ac" }, { "url": "https://git.kernel.org/stable/c/5570d6c8b320dbcc602617ee08c27ce752fed65a" }, { "url": "https://git.kernel.org/stable/c/3b9aa62d78ce80de47af2db472ff452398755213" }, { "url": "https://git.kernel.org/stable/c/f4461654374576e9d5d0245fd534c46ad8509051" }, { "url": "https://git.kernel.org/stable/c/dc20050b6b12ca58066715d088e1a537535d938d" }, { "url": "https://git.kernel.org/stable/c/33d1469b0124cc0baaea7a2032123b77a81e0940" } ], "title": "netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state", "x_generator": { "engine": "bippy-1.2.0" } } } }