Use After Free Affecting kernel-tools-libs-devel package, versions <0:4.18.0-553.117.1.el8_10


Severity

Recommended
medium

Based on Rocky Linux security rating.

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
0.81% (53rd percentile)

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  • Snyk IDSNYK-ROCKY8-KERNELTOOLSLIBSDEVEL-16048573
  • published14 Apr 2026
  • disclosed4 Mar 2026

Introduced: 4 Mar 2026

CVE-2026-23231  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Rocky-Linux:8 kernel-tools-libs-devel to version 0:4.18.0-553.117.1.el8_10 or higher.
This issue was patched in RLSA-2026:6571.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-tools-libs-devel package and not the kernel-tools-libs-devel package as distributed by Rocky-Linux. See How to fix? for Rocky-Linux:8 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1