A PoC of `execSan` with `pytorch-lightning-1.5.10` (#7827)

* A PoC of `execSan` with `pytorch-lightning-1.5.10`

infra/experimental/sanitizers/ExecSan/Makefile

@@ -13,5 +13,11 @@ target: target.cpp
 test:  all vuln.dict
 	./execSan ./target -dict=vuln.dict
 
+pytorch-lightning-1.5.10:
+	cp execSan.cpp PoEs/pytorch-lightning-1.5.10/; \
+	cd PoEs/pytorch-lightning-1.5.10/; \
+	docker build . --tag execsan_pytorch-lightning; \
+	docker run -t execsan_pytorch-lightning:latest;
+
 clean:
 	rm -f execSan /tmp/tripwire target

infra/experimental/sanitizers/ExecSan/PoEs/pytorch-lightning-1.5.10/Dockerfile

@@ -0,0 +1,32 @@
+# 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.
+#
+# Build and run the proof of error in pytorch-lightning.
+
+FROM gcr.io/oss-fuzz-base/base-builder-python
+
+RUN apt update && \
+  apt install -y vim && \
+  git clone \
+    --depth 1 \
+    --branch 1.5.10 \
+    https://github.com/PyTorchLightning/pytorch-lightning.git
+
+COPY ./build.sh $SRC
+RUN  ./build.sh
+
+COPY . $SRC
+RUN make execSan
+
+CMD ["make", "run"]

infra/experimental/sanitizers/ExecSan/PoEs/pytorch-lightning-1.5.10/Makefile

@@ -0,0 +1,12 @@
+.POSIX:
+CXX     = clang++
+CFLAGS = -std=c++17 -Wall -Wextra -O3 -g3
+
+execSan: execSan.cpp
+	$(CXX) $(CFLAGS) -lpthread -o $@ $^
+
+run: clean execSan fuzz_pytorch_lightning.py
+	./execSan ./fuzz_pytorch_lightning.py -dict=vuln.dict
+
+clean:
+	rm -f execSan /tmp/tripwire

infra/experimental/sanitizers/ExecSan/PoEs/pytorch-lightning-1.5.10/build.sh

@@ -0,0 +1,25 @@
+#!/bin/bash -eu
+# 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.
+#
+################################################################################
+
+# Build and install project (using current CFLAGS, CXXFLAGS).
+cd pytorch-lightning
+pip3 install .
+
+# Build fuzzers in $OUT.
+for fuzzer in $(find $SRC -name '*_fuzzer.py'); do
+  compile_python_fuzzer $fuzzer
+done

infra/experimental/sanitizers/ExecSan/PoEs/pytorch-lightning-1.5.10/fuzz_pytorch_lightning.py

@@ -0,0 +1,65 @@
+#!/usr/local/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.
+#
+################################################################################
+"""Exploit pytorch lightning with fuzzer's input as a random env variable.
+
+This PoC is extended from a report in GitHub Advisory Database:
+https://github.com/advisories/GHSA-r5qj-cvf9-p85h
+The original report documents an exploit using a specific environment variable,
+we show a way to achieve the same exploit with an arbitrary env variable.
+"""
+
+import os
+import sys
+import atheris
+
+with atheris.instrument_imports():
+  from pytorch_lightning import Trainer
+  from pytorch_lightning.utilities.argparse import parse_env_variables
+
+
+def prepare_fuzzing_input(data):
+  """Prepare the data needed by the exploit with input data from fuzzers."""
+  data = data.replace(b'\0', b'')
+  env_name = 'AN_ARBITRARY_ENV_NAME'
+  return data, env_name
+
+
+def exploit_target(env_value, env_name):
+  """This target is based on a snippet from the official documentation of
+  `parse_env_variables`:
+  https://pytorch-lightning.readthedocs.io/en/stable/api/pytorch_lightning.utilities.argparse.html  # pylint: disable=line-too-long
+  It might not be the most realistic example,
+  but serves as a PoC to show that execSan works for Python."""
+  os.environb[env_name.encode()] = env_value
+  parse_env_variables(Trainer, template=env_name)
+
+
+def TestOneInput(data):  # pylint: disable=invalid-name
+  """Exploit the target only with input data from fuzzers."""
+  env_value, env_name = prepare_fuzzing_input(data)
+  exploit_target(env_value, env_name)
+
+
+def main():
+  """Fuzz target with atheris."""
+  atheris.Setup(sys.argv, TestOneInput)
+  atheris.Fuzz()
+
+
+if __name__ == '__main__':
+  main()

infra/experimental/sanitizers/ExecSan/PoEs/pytorch-lightning-1.5.10/vuln.dict

@@ -0,0 +1 @@
+"os.system('/tmp/tripwire')"