decode: fix possible NULL dereference (#189)

fluent · Oct 19, 2023 · d0b9aee · d0b9aee
1 parent 16aa119
commit d0b9aee
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/src/cmt_decode_msgpack.c b/src/cmt_decode_msgpack.c
@@ -977,8 +977,11 @@ static int unpack_basic_type_meta(mpack_reader_t *reader, size_t index, void *co
     result = cmt_mpack_unpack_map(reader, callbacks, context);
 
     if (CMT_DECODE_MSGPACK_SUCCESS == result) {
-        decode_context->map->label_count = cfl_list_size(&decode_context->map->label_keys);
+	if (decode_context->map == NULL || decode_context->map->parent == NULL) {
+            return CMT_DECODE_MSGPACK_INVALID_ARGUMENT_ERROR;
+	}
 
+        decode_context->map->label_count = cfl_list_size(&decode_context->map->label_keys);
         if (decode_context->map->type == CMT_HISTOGRAM) {
             histogram = (struct cmt_histogram *) decode_context->map->parent;