numa: Reject duplicate node IDs

The same nodeid shouldn't appear multiple times in the command-line.

In addition to detecting command-line mistakes, this will fix a bug
where nb_numa_nodes may become larger than MAX_NODES (and cause
out-of-bounds access on the numa_info array).
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NHu Tao <hutao@cn.fujitsu.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

numa.c

@@ -62,6 +62,11 @@ static void numa_node_parse(NumaNodeOptions *node, QemuOpts *opts, Error **errp)
         return;
     }
 
+    if (numa_info[nodenr].present) {
+        error_setg(errp, "Duplicate NUMA nodeid: %" PRIu16, nodenr);
+        return;
+    }
+
     for (cpus = node->cpus; cpus; cpus = cpus->next) {
         if (cpus->value > MAX_CPUMASK_BITS) {
             error_setg(errp, "CPU number %" PRIu16 " is bigger than %d",