CVE-2022-48985

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

net: mana: Fix race on per-CQ variable napi work_done

After calling napi_complete_done(), the NAPIF_STATE_SCHED bit may be

cleared, and another CPU can start napi thread and access per-CQ variable,

cq->work_done. If the other thread (for example, from busy_poll) sets

it to a value >= budget, this thread will continue to run when it should

stop, and cause memory corruption and panic.

To fix this issue, save the per-CQ work_done variable in a local variable

before napi_complete_done(), so it won't be corrupted by a possible

concurrent thread after napi_complete_done().

Also, add a flag bit to advertise to the NIC firmware: the NAPI work_done

variable race is fixed, so the driver is able to reliably support features

like busy_poll.