RDMA/rxe: Fix unsafe drain work queue code

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix unsafe drain work queue code If create_qp does not fully succeed it is possible for qp cleanup code to attempt to drain the send or recv work queues before the queues have been created causing a seg fault. This patch checks to see if the queues exist before attempting to drain them.

References

• https://git.kernel.org/stable/c/da572f6313aeead1f79e0810666bd8d8ffc794d4
• https://git.kernel.org/stable/c/d366642b3099bd322375f5b71ba84ab1d586cd6d
• https://git.kernel.org/stable/c/5993b75d0bc71cd2b441d174b028fc36180f032c