CVE-2026-74663

In the Linux kernel, the following vulnerability has been resolved:

net/sched: reject overly deep qdisc hierarchies

Deep qdisc hierarchies can lead to excessive recursion in qdisc tree

walkers and exhaust the kernel stack. The existing loop check does not

cover the create-and-graft path, so a hierarchy can still be extended by

creating a new child qdisc below an already deep parent.

Store the hierarchy depth in struct Qdisc and update it when qdiscs are

grafted. Reject new child qdiscs once the parent is already at the maximum

allowed depth.