1 files changed, 4 insertions, 0 deletions
diff --git a/ext/psych/yaml/reader.c b/ext/psych/yaml/reader.c
index 4e48add7b8..f1a06deb9d 100644
--- a/ext/psych/yaml/reader.c
+++ b/ext/psych/yaml/reader.c
@@ -460,6 +460,10 @@ yaml_parser_update_buffer(yaml_parser_t *parser, size_t length)
 
     }
 
+    if (parser->offset >= PTRDIFF_MAX)
+        return yaml_parser_set_reader_error(parser, "input is too long",
+                PTRDIFF_MAX, -1);
+
     return 1;
 }