CVE-2026-23392: netfilter: nf_tables: release flowtable after rcu grace period on error
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nftables: release flowtable after rcu grace period on error
Call synchronizercu() 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 nfnetlinkhook 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 synchronizercu().
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 nfnetlinkhook path when dumping hooks.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-23392?
The severity of CVE-2026-23392 is considered medium as it involves a release flowtable issue in the Linux kernel that can lead to potential system instability.
How do I fix CVE-2026-23392?
To fix CVE-2026-23392, update your Linux kernel to a version that includes the patch mentioned in the vulnerability advisory.
What systems are affected by CVE-2026-23392?
CVE-2026-23392 affects the Linux kernel, specifically those versions that utilize the netfilter framework.
Is CVE-2026-23392 related to network security?
Yes, CVE-2026-23392 is related to network security as it involves the netfilter subsystem, which is responsible for handling network packet filtering.
What are the potential impacts of CVE-2026-23392?
The potential impacts of CVE-2026-23392 include system crashes or instability due to improper resource management after an error in the netfilter subsystem.