netem

The netem tag covers a Linux kernel security issue in the network traffic-control subsystem. Its featured discussion examines CVE-2026-63983, a denial-of-service vulnerability affecting NetEm, Linux’s network-emulation queuing discipline. The flaw can repeatedly duplicate packets configured for duplication when they pass through certain queueing hierarchies. Potential consequences include soft lockups, uncontrolled memory consumption, and system crashes, rather than data theft or remote code execution. The coverage also explains the upstream fix, which marks duplicated packets directly instead of temporarily changing shared queue state, helping prevent packet loops and improve kernel stability.