In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_qfq: do not free existing class in qfq_change_class() Fixes qfq_change_class() error case. cl->qdisc and cl should only be freed if a new class and qdisc were allocated, or we risk various UAF.
https://git.kernel.org/stable/c/e9d8f11652fa08c647bf7bba7dd8163241a332cd
https://git.kernel.org/stable/c/3879cffd9d07aa0377c4b8835c4f64b4fb24ac78
https://git.kernel.org/stable/c/362e269bb03f7076ba9990e518aeddb898232e50