In the Linux kernel before 6.1.6, a NULL pointer dereference bug in the traffic control subsystem allows an unprivileged user to trigger a denial of service (system crash) via a crafted traffic control configuration that is set up with "tc qdisc" and "tc class" commands. This affects qdisc_graft in net/sched/sch_api.c.
https://www.spinics.net/lists/netdev/msg555705.html
https://www.debian.org/security/2023/dsa-5324
https://tldp.org/HOWTO/Traffic-Control-HOWTO/components.html
https://lists.debian.org/debian-lts-announce/2023/05/msg00006.html
https://lists.debian.org/debian-lts-announce/2023/03/msg00000.html
https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.1.6