Deep Dive: The Rewritten AF_UNIX Garbage Collector and CVE-2025-40214
By
@AcherirMoe
Summary
A detailed technical walkthrough of the rewritten AF_UNIX garbage collector in the Linux kernel. The article explains how the GC handles unreachable sockets sent via SCM_RIGHTS, describes the new graph/Strongly-Connected-Components model, and analyzes a Use-After-Free bug (CVE-2025-40214) caused by an uninitialized scc_index field. Includes two reproducers for the bug.
Source
Hacker NewsDeep Dive: The Rewritten AF_UNIX Garbage Collector and CVE-2025-40214mohandacherir.github.ioKey quotes
· 4 pulledThe AF_UNIX garbage collector is an interesting piece of the kernel.
It exists because sockets can be sent with SCM_RIGHTS but they can become unreachable from user-space while still being kept alive by the kernel, which is not memory efficient.
Not long ago, the subsystem was rewritten from scratch on top of a graph/Strongly-Connected-Components model; but it is still bug prone.
This post walks the rewrite end-to-end, and discusses a Use-After-Free bug.
You might also wanna read
Working Exploit Released for Linux Kernel Use-After-Free Flaw CVE-2026-23111 Enabling Local Root Access
Security researchers have released a working exploit for CVE-2026-23111, a Linux kernel use-after-free vulnerability in nf_tables. The flaw
hendryadrian.com·15d ago
NVD - CVE-2026-11463
nvd.nist.gov·16d ago
CVE-2026-12043: Heap Double-Free Vulnerability Discovered in AWS Common Runtime aws-c-http Library
AWS disclosed CVE-2026-12043, a heap double-free vulnerability in the AWS Common Runtime aws-c-http library. The issue stems from improper h
aws.amazon.com·10d agoCVE-2025-9032: Heap Buffer Out-of-Bounds Read Vulnerability in Avira Antivirus Engine
A heap buffer out-of-bounds read vulnerability (CVE-2025-9032) has been discovered in the Avira Antivirus engine. The flaw occurs when scann
nvd.nist.gov·11d ago
Python 3.14 Delivers JIT Compiler and GIL-Free Concurrency
Python 3.14 introduces two major features: a new JIT (Just-In-Time) compiler and the removal of the Global Interpreter Lock (GIL), enabling
towardsdatascience.com·1d agoCVE-2025-14098: Heap Buffer Overflow Vulnerability in Avira Antivirus Engine (Pre-8.3.70.104)
A heap buffer out-of-bounds write vulnerability (CVE-2025-14098) exists in the Avira Antivirus engine due to an integer overflow when scanni
nvd.nist.gov·11d agoComments
Sign in to join the conversation.
No comments yet. Be the first.