yosys/libs/fst/00_PATCH_wx_len_overread.patch

--- fstapi.cc
+++ fstapi.cc
@@ -6072,6 +6072,7 @@ for(;;)
                                         }
 
                                 wx_len = snprintf(wx_buf, 32, "r%.16g", d);
+                                if (wx_len > 32 || wx_len < 0) wx_len = 32;
                                 fstWritex(xc, wx_buf, wx_len);
                                 }
                         }