In the Linux kernel, the following vulnerability has been resolved:
ksmbd: retain connection for pending notify work
Deferred CHANGE_NOTIFY work keeps an async message ID after the original request work is released. A durable handle can outlive its connection, so the connection teardown can destroy its async IDA before the handle close releases the pending notify work.
Give the synthetic deferred work a connection reference. Release it after the async ID in ksmbd_free_work_struct(). This keeps the async IDA alive until the deferred work is released, even when the original connection has already left the connection list.
During server shutdown there is no client to receive a cleanup response. Skip the write and only release the pending work.