CVE-2023-52923 netfilter: nf_tables: adapt set backend to use GC transaction API
A race condition in the Linux kernel netfilter subsystem could lead to system instability or denial of service due to improper garbage collection handling.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-52923?
CVE-2023-52923 is a high-severity vulnerability in Linux kernel, published on 20 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
netfilter: nf_tables: adapt set backend to use GC transaction API
Use the GC transaction API to replace the old and buggy gc API and the busy mark approach.
No set elements are removed from async garbage collection anymore, instead the _DEAD bit is set on so the set element is not visible from lookup path anymore. Async GC enqueues transaction work that might be aborted and retried later.
rbtree and pipapo set backends does not set on the _DEAD bit from the sync GC path since this runs in control plane path where mutex is held. In this case, set elements are deactivated, removed and then released via RCU callback, sync GC never fails.
Which versions are affected by CVE-2023-52923?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-52923?
Apply the vendor's patch.
Is CVE-2023-52923 being exploited?
There is no known exploitation of CVE-2023-52923 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-52923, DEBIAN-CVE-2023-52923, GHSA-f2qv-j847-m6vp, UBUNTU-CVE-2023-52923.