1 files changed, 14 insertions, 0 deletions

diff --git a/source/pdf/pdf-xref.c b/source/pdf/pdf-xref.c
index 723b543c0..ed09094cb 100644
--- a/source/pdf/pdf-xref.c
+++ b/source/pdf/pdf-xref.c
@@ -1576,6 +1576,19 @@ pdf_load_obj_stm(fz_context *ctx, pdf_document *doc, int num, pdf_lexbuf *buf, i
         {
                 objstm = pdf_load_object(ctx, doc, num);
 
+                if (pdf_obj_marked(ctx, objstm))
+                        fz_throw(ctx, FZ_ERROR_GENERIC, "recursive object stream lookup");
+        }
+        fz_catch(ctx)
+        {
+                pdf_drop_obj(ctx, objstm);
+                fz_rethrow(ctx);
+        }
+
+        fz_try(ctx)
+        {
+                pdf_mark_obj(ctx, objstm);
+
                 count = pdf_to_int(ctx, pdf_dict_get(ctx, objstm, PDF_NAME_N));
                 first = pdf_to_int(ctx, pdf_dict_get(ctx, objstm, PDF_NAME_First));
 
@@ -1655,6 +1668,7 @@ pdf_load_obj_stm(fz_context *ctx, pdf_document *doc, int num, pdf_lexbuf *buf, i
                 fz_drop_stream(ctx, stm);
                 fz_free(ctx, ofsbuf);
                 fz_free(ctx, numbuf);
+                pdf_unmark_obj(ctx, objstm);
                 pdf_drop_obj(ctx, objstm);
         }
         fz_catch(ctx)