Fix division by zero issue with malformed file

src/decoder/mod.rs

@@ -1309,6 +1309,14 @@ impl<R: Read + Seek> Decoder<R> {
             let tile_width = usize::try_from(self.get_tag_u32(Tag::TileWidth)?)?;
             let tile_length = usize::try_from(self.get_tag_u32(Tag::TileLength)?)?;
 
+            if tile_width == 0 {
+                return Err(TiffFormatError::InvalidTagValueType(Tag::TileWidth).into());
+            }
+
+            if tile_length == 0 {
+                return Err(TiffFormatError::InvalidTagValueType(Tag::TileLength).into());
+            }
+
             let tiles_across = (usize::try_from(self.width)? + tile_width - 1) / tile_width;
             let tiles_down = (usize::try_from(self.height)? + tile_length - 1) / tile_length;
 

tests/decode_images.rs

@@ -284,3 +284,18 @@ fn test_tiled_incremental() {
         }
     }
 }
+
+#[test]
+fn test_div_zero() {
+    let image = [
+        73, 73, 42, 0, 8, 0, 0, 0, 8, 0, 0, 1, 4, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 40, 1, 0, 0,
+        0, 158, 0, 0, 251, 3, 1, 3, 0, 1, 0, 0, 0, 1, 0, 0, 39, 6, 1, 3, 0, 1, 0, 0, 0, 0, 0, 0, 0,
+        17, 1, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 3, 0, 1, 0, 0, 0, 158, 0, 0, 251, 67, 1, 3, 0,
+        1, 0, 0, 0, 40, 0, 0, 0, 66, 1, 4, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 48, 178, 178, 178, 178,
+        178, 178, 178,
+    ];
+
+    let mut decoder = tiff::decoder::Decoder::new(std::io::Cursor::new(&image)).unwrap();
+
+    let _ = decoder.read_image();
+}