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/f06f7635499bc806cbe2bbc8805c7cef8b1edddf
https://git.kernel.org/stable/c/e9d8f11652fa08c647bf7bba7dd8163241a332cd
https://git.kernel.org/stable/c/cff6cd703f41d8071995956142729e4bba160363
https://git.kernel.org/stable/c/3879cffd9d07aa0377c4b8835c4f64b4fb24ac78
https://git.kernel.org/stable/c/362e269bb03f7076ba9990e518aeddb898232e50
https://git.kernel.org/stable/c/2a64fb9b47afffeb5dbab5fd3a518e1436dcc90e
https://git.kernel.org/stable/c/0a234660dc70ce45d771cbc76b20d925b73ec160