font fuzzer

Tests/oss-fuzz/build.sh

@@ -43,4 +43,5 @@ ASAN_OPTIONS=\$ASAN_OPTIONS:symbolize=1:external_symbolizer_path=\$this_dir/llvm
   chmod u+x $OUT/$fuzzer_basename
 done
 
-find Tests/images Tests/icc Tests/fonts -print | zip -q $OUT/fuzz_pillow_seed_corpus.zip -@
+find Tests/images Tests/icc -print | zip -q $OUT/fuzz_pillow_seed_corpus.zip -@
+find Tests/fonts -print | zip -q $OUT/fuzz_font_seed_corpus.zip -@

Tests/oss-fuzz/fuzz_font.py

@@ -0,0 +1,47 @@
+#!/usr/bin/python3
+
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import io
+import sys
+import warnings
+
+import atheris_no_libfuzzer as atheris
+
+from PIL import Image, ImageDraw, ImageFont
+
+
+def TestOneInput(data):
+    try:
+        with ImageFont.load(io.BytesIO(data)) as font:
+            font.getsize_multiline("ABC\nAaaa")
+            font.getmask("test text")
+            with Image.new(mode="RGBA", size=(200, 200)) as im:
+                draw = ImageDraw.Draw(im)
+                draw.text((10,10), "Test Text", font)
+    except Exception:
+        # We're catching all exceptions because Pillow's exceptions are
+        # directly inheriting from Exception.
+        return
+    return
+
+
+def main():
+    atheris.Setup(sys.argv, TestOneInput, enable_python_coverage=True)
+    atheris.Fuzz()
+
+
+if __name__ == "__main__":
+    main()