CVE-2026-23231

Description

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 vialist_add_tail_rcu() (in nft_chain_add()) before registering hooks.If nf_tables_register_hook() then fails, the error path callsnft_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 destroyso that all RCU readers -- both dump threads and in-flight packetevaluation -- have finished before the chain is freed.

Risk Information

Base Score

7.8

MODERATE

Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Score

Exploitation Probability

0.013

Associated Vulnerability

No records found

Patch Details

No records found

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234