ksmbd: fix a missing return value check bug

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

ksmbd: fix a missing return value check bug

In the smb2_send_interim_resp(), if ksmbd_alloc_work_struct()

fails to allocate a node, it returns a NULL pointer to the

in_work pointer. This can lead to an illegal memory write of

in_work->response_buf when allocate_interim_rsp_buf() attempts

to perform a kzalloc() on it.

To address this issue, incorporating a check for the return

value of ksmbd_alloc_work_struct() ensures that the function

returns immediately upon allocation failure, thereby preventing

the aforementioned illegal memory access.