12001 cpu_uarray_free(NULL) panics

@@ -8,11 +8,11 @@
  * source.  A copy of the CDDL is also available via the Internet at
  * http://www.illumos.org/license/CDDL.
  */
 
 /*
- * Copyright (c) 2018, Joyent, Inc.
+ * Copyright 2019 Joyent, Inc.
  */
 
 #include <sys/cpu_uarray.h>
 #include <sys/sysmacros.h>
 #include <sys/cpuvar.h>

@@ -43,10 +43,11 @@
 }
 
 void
 cpu_uarray_free(cpu_uarray_t *cua)
 {
+        if (cua != NULL)
         kmem_free(cua, cpu_uarray_size(cua->cu_nr_items));
 }
 
 uint64_t
 cpu_uarray_sum(cpu_uarray_t *cua, size_t index)