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

ublk: make sure ubq->canceling is set when queue is frozen

Now ublk driver depends on `ubq->canceling` for deciding if the request
can be dispatched via uring_cmd & io_uring_cmd_complete_in_task().

Once ubq->canceling is set, the uring_cmd can be done via ublk_cancel_cmd()
and io_uring_cmd_done().

So set ubq->canceling when queue is frozen, this way makes sure that the
flag can be observed from ublk_queue_rq() reliably, and avoids
use-after-free on uring_cmd.

https://git.kernel.org/stable/c/5491400589e7572c2d2627ed6384302f7672aa1d

https://git.kernel.org/stable/c/7e3497d7dacb5aee69dd9be842b778083cae0e75

https://git.kernel.org/stable/c/8741d0737921ec1c03cf59aebf4d01400c2b461a

https://git.kernel.org/stable/c/9158359015f0eda00e521e35b7bc7ebce176aebf