Add fuzzer with 1MB size limits decoding image

fuzz/fuzz_targets/decode_image.rs

@@ -0,0 +1,19 @@
+#![no_main]
+use libfuzzer_sys::fuzz_target;
+
+fuzz_target!(|data: &[u8]| {
+    let mut decoder = if let Ok(d) = tiff::decoder::Decoder::new(std::io::Cursor::new(data)) {
+        d
+    } else {
+        return;
+    };
+
+    let mut limits = tiff::decoder::Limits::default();
+    limits.decoding_buffer_size = 1_000_000;
+    limits.ifd_value_size = 1_000_000;
+    limits.intermediate_buffer_size = 1_000_000;
+
+    decoder = decoder.with_limits(limits);
+
+    let _ = decoder.read_image();
+});