CVE-2026-23392

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_tables: release flowtable after rcu grace period on error

Call synchronize_rcu() after unregistering the hooks from error path,

since a hook that already refers to this flowtable can be already

registered, exposing this flowtable to packet path and nfnetlink_hook

control plane.

This error path is rare, it should only happen by reaching the maximum

number hooks or by failing to set up to hardware offload, just call

synchronize_rcu().

There is a check for already used device hooks by different flowtable

that could result in EEXIST at this late stage. The hook parser can be

updated to perform this check earlier to this error path really becomes

rarely exercised.

Uncovered by KASAN reported as use-after-free from nfnetlink_hook path

when dumping hooks.