Homepage

Use After Free The advisory has been revoked - it doesn't affect any version of package perf  (opens in a new tab)

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
0.79% (53rd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-ALMALINUX10-PERF-15930761
  • published8 Apr 2026
  • disclosed6 Apr 2026
Report a new vulnerability Found a mistake?

Introduced: 6 Apr 2026

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

Amendment

The AlmaLinux security team deemed this advisory irrelevant for AlmaLinux:10.

NVD Description

Note: Versions mentioned in the description apply only to the upstream perf package and not the perf package as distributed by AlmaLinux.

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.

References