diff --git a/tools/input/annexb.rs b/tools/input/annexb.rs
index 8b8943959..7a41bd5f9 100644
--- a/tools/input/annexb.rs
+++ b/tools/input/annexb.rs
@@ -125,6 +125,9 @@ unsafe fn parse_obu_header(
     buf = buf.offset(1);
     buf_size -= 1;
     if extension_flag != 0 {
+        if buf_size == 0 {
+            return -1;
+        }
         buf = buf.offset(1);
         buf_size -= 1;
     }
diff --git a/tools/input/section5.rs b/tools/input/section5.rs
index a0b2fdda0..afae4adf2 100644
--- a/tools/input/section5.rs
+++ b/tools/input/section5.rs
@@ -104,6 +104,9 @@ unsafe fn parse_obu_header(
     buf_size -= 1;
     if extension_flag != 0 {
         buf = buf.offset(1);
+        if buf_size == 0 {
+            return -1;
+        }
         buf_size -= 1;
     }
     if has_size_flag != 0 {