Initial release

fuzz/fuzz_image.cpp

@@ -0,0 +1,33 @@
+// libFuzzer harness for the image upload path: arbitrary bytes ->
+// t2_preprocess_image_bytes (stb_image decode -> alpha bbox crop ->
+// premultiply -> PIL-compatible Lanczos resize).
+//
+// This is the demo server's untrusted-input surface: the Go server hands
+// uploaded bytes straight to this function. GGUF model files are trusted
+// assets and deliberately not fuzzed here (privacy-filter.cpp threat model).
+//
+// Build via -DTRELLIS2_FUZZ=ON (clang only); run:
+//   ./build-fuzz/fuzz/fuzz_image corpus_image/ -max_len=1048576
+//
+// Success invariant: the function either fails cleanly (nonzero + error
+// message) or fills exactly out_size^2*3 bytes. Any crash/leak/UB is a bug.
+
+#include "../trellis2_capi.h"
+
+#include <cstdint>
+#include <cstring>
+#include <vector>
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t * data, size_t size) {
+    if (size == 0 || size > (32u << 20)) {
+        return 0;
+    }
+
+    // Small output target keeps per-input cost low; the resampler code path
+    // is identical for any out_size.
+    static thread_local std::vector<unsigned char> out(64 * 64 * 3);
+    char err[256] = {0};
+
+    (void) t2_preprocess_image_bytes(data, (int) size, 64, out.data(), err, sizeof(err));
+    return 0;
+}