flask: add jinja compiler fuzzers (#7685)

* flask: add jinja compiler fuzzers

* nit

projects/flask/fuzz_jinja_compile_expr.py

@@ -0,0 +1,39 @@
+#!/usr/bin/python3
+# Copyright 2022 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 sys
+import atheris
+
+with atheris.instrument_imports():
+    import jinja2
+
+def TestOneInput(data):
+    fdp = atheris.FuzzedDataProvider(data)
+    env = jinja2.Environment()
+    try:
+      v1 = env.compile_expression(fdp.ConsumeString(sys.maxsize))
+    except jinja2.TemplateSyntaxError:
+      return
+    except SyntaxError:
+      return
+    except RecursionError:
+      return
+    return
+
+def main():
+    atheris.Setup(sys.argv, TestOneInput, enable_python_coverage=True)
+    atheris.Fuzz()
+
+if __name__ == "__main__":
+    main()

projects/flask/fuzz_jinja_compile_templates.py

@@ -0,0 +1,47 @@
+#!/usr/bin/python3
+# Copyright 2022 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 sys
+import atheris
+
+with atheris.instrument_imports():
+    from jinja2.environment import Environment
+    from jinja2.loaders import DictLoader
+
+def TestOneInput(data):
+    fdp = atheris.FuzzedDataProvider(data)
+    template_str = fdp.ConsumeString(sys.maxsize)
+
+    tmp_path = "/tmp/mytemplates"
+    temp_file = os.path.join(tmp_path, "template.jinja2")
+    if not os.path.isdir(tmp_path):
+        os.mkdir(tmp_path)
+    if os.path.isfile(temp_file):
+        os.remove(temp_file)
+    with open(temp_file, "wb") as fd:
+        fd.write(data)
+
+    env = Environment(loader=DictLoader({"foo": template_str}))
+    try:
+        env.compile_templates(tmp_path, zip=None)
+    except RecursionError:
+        return
+    return
+
+def main():
+    atheris.Setup(sys.argv, TestOneInput, enable_python_coverage=True)
+    atheris.Fuzz()
+
+if __name__ == "__main__":
+    main()