iw_cxgb4: remove the stid on listen create failure

If a listen create fails, then the server tid (stid) is incorrectly left
in the stid idr table, which can cause a touch-after-free if the stid
is looked up and the already freed endpoint is touched.  So make sure
and remove it in the error path.

Cc: stable@vger.kernel.org
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/cxgb4/cm.c

@@ -3462,7 +3462,7 @@ int c4iw_create_listen(struct iw_cm_id *cm_id, int backlog)
 		cm_id->provider_data = ep;
 		goto out;
 	}
-
+	remove_handle(ep->com.dev, &ep->com.dev->stid_idr, ep->stid);
 	cxgb4_free_stid(ep->com.dev->rdev.lldi.tids, ep->stid,
 			ep->com.local_addr.ss_family);
 fail2: