item: Disallow grid boxes with extra bytes

There cannot be any trailing bytes in the grid box. PiperOrigin-RevId: 655207768
webmproject · Jul 23, 2024 · 9b963c9 · 9b963c9
1 parent 94464a9
commit 9b963c9
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diff --git a/poc_b_354563288.avif b/poc_b_354563288.avif
diff --git a/src/decoder/item.rs b/src/decoder/item.rs
@@ -136,6 +136,11 @@ impl Item {
                 "grid dimensions too large".into(),
             ));
         }
+        if stream.has_bytes_left()? {
+            return Err(AvifError::InvalidImageGrid(
+                "found unknown extra bytes in the grid box".into(),
+            ));
+        }
         Ok(())
     }