IB/hfi1: Ensure VL index is within bounds

Improve the safety of the code and ensure the array cannot be indexed
out of bounds when picking the CPU for a given SDMA engine.

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/hfi1/sdma.c

@@ -962,6 +962,11 @@ ssize_t sdma_set_cpu_to_sde_map(struct sdma_engine *sde, const char *buf,
 			continue;
 		}
 
+		if (vl >= ARRAY_SIZE(rht_node->map)) {
+			ret = -EINVAL;
+			goto out;
+		}
+
 		rht_node = rhashtable_lookup_fast(dd->sdma_rht, &cpu,
 						  sdma_rht_params);
 		if (!rht_node) {