netfilter: nf_tables: fix use-after-free in nf_tables_addchain()
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.1.165, 6.6.128, 6.12.75, 6.18.14, 6.19.4
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- 1 on Exploit-DB
- Exploitation: none
- Automatable: no
- Technical impact: total
Summary
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix use-after-free in nf_tables_addchain() nf_tables_addchain() publishes the chain to table->chains via list_add_tail_rcu() (in nft_chain_add()) before registering hooks. If nf_tables_register_hook() then fails, the error path calls nft_chain_del() (list_del_rcu()) followed by nf_tables_chain_destroy() with no RCU grace period in between. This creates two use-after-free conditions: 1) Control-plane: nf_tables_dump_chains() traverses table->chains under rcu_read_lock(). A concurrent dump can still be walking the chain when the error path frees it. 2) Packet path: for NFPROTO_INET, nf_register_net_hook() briefly installs the IPv4 hook before IPv6 registration fails. Packets entering nft_do_chain() via the transient IPv4 hook can still be dereferencing chain->blob_gen_X when the error path frees the chain. Add synchronize_rcu() between nft_chain_del() and the chain destroy so that all RCU readers -- both dump threads and in-flight packet evaluation -- have finished before the chain is freed.
Timeline
- CVE published
- Public exploit on Exploit-DB
EDB-52549
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- Linux Linux
From 91c7b38dc9f0de4f7f444b796d14476bc12df7bc · fixed in 2a6586ecfa4ce1413daaafee250d2590e05f1a33; From 91c7b38dc9f0de4f7f444b796d14476bc12df7bc · fixed in 7017745068a9068904e1e7a1b170a5785647cc81; From 91c7b38dc9f0de4f7f444b796d14476bc12df7bc · fixed in f3fe58ce37926a10115ede527d59b91bcc05400a; From 91c7b38dc9f0de4f7f444b796d14476bc12df7bc · fixed in dbd0af8083dd201f07c49110b2ee93710abdff28; From 91c7b38dc9f0de4f7f444b796d14476bc12df7bc · fixed in 2f9a4ffeb763aec822f8ff3d1e82202d27d46d4b; From 91c7b38dc9f0de4f7f444b796d14476bc12df7bc · fixed in 71e99ee20fc3f662555118cf1159443250647533
- Linux Linux
3.16
- KernelLinux
From 3.16.0 · fixed in 6.1.165; From 6.2.0 · fixed in 6.6.128; From 6.7.0 · fixed in 6.12.75; From 6.13.0 · fixed in 6.18.14; From 6.19.0 · fixed in 6.19.4