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

RDMA/ipoib: Drain RCU callbacks during module teardown

IPoIB reclamation completions can be signaled from inside an RCU callback.
Teardown can wake before the callback returns and unload ib_ipoib while its
code is still executing.

Client registration failure can also remove already-added devices and queue
callbacks. Wait after client and workqueue teardown.