CVE-2020-15193 (published 2020-09-25T19:15Z)

In Tensorflow before versions 2.2.1 and 2.3.1, the implementation of `dlpack.to_dlpack` can be made to use uninitialized memory resulting in further memory corruption. This is because the pybind11 glue code assumes that the argument is a tensor. However, there is nothing stopping users from passing in a Python object instead of a tensor. The uninitialized memory address is due to a `reinterpret_cast` Since the `PyObject` is a Python object, not a TensorFlow Tensor, the cast to `EagerTensor` fails. The issue is patched in commit 22e07fb204386768e5bcbea563641ea11f96ceb8 and is released in TensorFlow versions 2.2.1, or 2.3.1.

Severity: MEDIUM
CVSS v2 base score: 5.5 (AV:N/AC:L/Au:S/C:N/I:P/A:P)
CVSS v3 base score: 7.1, HIGH (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L)

Weakness information:
cwe_id: CWE-908
cwe_name: Use of Uninitialized Resource
description: The product uses or accesses a resource that has not been initialized.
extended_description: When a resource has not been properly initialized, the product may behave unexpectedly. This may lead to a crash or invalid memory access, but the consequences vary depending on the type of resource and how it is used within the product.
         

Fix information:
repo_url: https://github.com/tensorflow/tensorflow
commit_details: repo_url: https://github.com/tensorflow/tensorflow
author: Mihai Maruseac
author_date: 2020-09-18 19:14:17-07:00
msg: Fix multiple vulnerabilities in `tf.experimental.dlpack.to_dlpack`.

We have a use after free caused by memory coruption, a segmentation fault caused by memory corruption, several memory leaks and an undefined behavior when taking the reference of a nullptr.

PiperOrigin-RevId: 332568894
Change-Id: Ife0fc05e103b35325094ae5d822ee5fdea764572
repository: repo_url: https://github.com/tensorflow/tensorflow
repo_name: tensorflow/tensorflow
description: An Open Source Machine Learning Framework for Everyone
repo_language: C++
owner: tensorflow
file_changes: filename: dlpack.cc
change_type: ModificationType.MODIFY
diff: @@ -249,21 +249,36 @@ void TFE_CallDLManagedTensorDeleter(void* dlm_ptr) {
 }
 
 void* TFE_HandleToDLPack(TFE_TensorHandle* h, TF_Status* status) {
+  auto tf_dlm_context = GetDlContext(h, status);
+  if (!status->status.ok()) {
+    return nullptr;
+  }
+
+  auto* tf_dlm_data = TFE_TensorHandleDevicePointer(h, status);
+  if (!status->status.ok()) {
+    return nullptr;
+  }
+
   const Tensor* tensor = GetTensorFromHandle(h, status);
   TF_DataType data_type = static_cast<TF_DataType>(tensor->dtype());
-  TensorReference tensor_ref(*tensor);  // This will call buf_->Ref()
 
+  auto tf_dlm_type = GetDlDataType(data_type, status);
+  if (!status->status.ok()) {
+    return nullptr;
+  }
+
+  TensorReference tensor_ref(*tensor);  // This will call buf_->Ref()
   auto* tf_dlm_tensor_ctx = new TfDlManagedTensorCtx(tensor_ref);
   tf_dlm_tensor_ctx->reference = tensor_ref;
 
   DLManagedTensor* dlm_tensor = &tf_dlm_tensor_ctx->tensor;
   dlm_tensor->manager_ctx = tf_dlm_tensor_ctx;
   dlm_tensor->deleter = &DLManagedTensorDeleter;
-  dlm_tensor->dl_tensor.ctx = GetDlContext(h, status);
+  dlm_tensor->dl_tensor.ctx = tf_dlm_context;
   int ndim = tensor->dims();
   dlm_tensor->dl_tensor.ndim = ndim;
-  dlm_tensor->dl_tensor.data = TFE_TensorHandleDevicePointer(h, status);
-  dlm_tensor->dl_tensor.dtype = GetDlDataType(data_type, status);
+  dlm_tensor->dl_tensor.data = tf_dlm_data;
+  dlm_tensor->dl_tensor.dtype = tf_dlm_type;
 
   std::vector<int64_t>* shape_arr = &tf_dlm_tensor_ctx->shape;
   std::vector<int64_t>* stride_arr = &tf_dlm_tensor_ctx->strides;
@@ -276,13 +291,14 @@ void* TFE_HandleToDLPack(TFE_TensorHandle* h, TF_Status* status) {
     (*stride_arr)[i] = (*shape_arr)[i + 1] * (*stride_arr)[i + 1];
   }
 
-  dlm_tensor->dl_tensor.shape = &(*shape_arr)[0];
+  dlm_tensor->dl_tensor.shape = shape_arr->data();
   // There are two ways to represent compact row-major data
   // 1) nullptr indicates tensor is compact and row-majored.
   // 2) fill in the strides array as the real case for compact row-major data.
   // Here we choose option 2, since some frameworks didn't handle the strides
   // argument properly.
-  dlm_tensor->dl_tensor.strides = &(*stride_arr)[0];
+  dlm_tensor->dl_tensor.strides = stride_arr->data();
+
   dlm_tensor->dl_tensor.byte_offset =
       0;  // TF doesn't handle the strides and byte_offsets here
   return static_cast<void*>(dlm_tensor);

programming_language: C++
filename: BUILD
change_type: ModificationType.MODIFY
diff: @@ -19,7 +19,6 @@ cuda_py_test(
     name = "dlpack_test",
     srcs = ["dlpack_test.py"],
     srcs_version = "PY2AND3",
-    tags = ["noasan"],  # TODO(b/159774807)
     deps = [
         ":dlpack",
         "//tensorflow/python/eager:test",

programming_language: R
filename: dlpack_test.py
change_type: ModificationType.MODIFY
diff: @@ -20,9 +20,11 @@ from __future__ import print_function
 from absl.testing import parameterized
 import numpy as np
 
+
 from tensorflow.python.dlpack import dlpack
 from tensorflow.python.framework import constant_op
 from tensorflow.python.framework import dtypes
+from tensorflow.python.framework import errors
 from tensorflow.python.framework import ops
 from tensorflow.python.platform import test
 from tensorflow.python.ops import array_ops
@@ -105,6 +107,12 @@ class DLPackTest(parameterized.TestCase, test.TestCase):
     self.assertRaisesRegex(Exception, ".* is not supported by dlpack",
                            UnsupportedComplex64)
 
+  def testMustPassTensorArgumentToDLPack(self):
+    with self.assertRaisesRegex(
+        errors.InvalidArgumentError,
+        "The argument to `to_dlpack` must be a TF tensor, not Python object"):
+      dlpack.to_dlpack([1])
+
 
 if __name__ == "__main__":
   ops.enable_eager_execution()

programming_language: Python
filename: tfe_wrapper.cc
change_type: ModificationType.MODIFY
diff: @@ -1358,9 +1358,16 @@ PYBIND11_MODULE(_pywrap_tfe, m) {
   // DLPack functions
   m.def("TFE_ToDlpackCapsule", [](py::handle& o) {
     PyObject* eager_tensor_pyobject_ptr = o.ptr();
-    TFE_TensorHandle* thandle = EagerTensor_Handle(eager_tensor_pyobject_ptr);
     tensorflow::Safe_TF_StatusPtr status =
         tensorflow::make_safe(TF_NewStatus());
+
+    if (!EagerTensor_CheckExact(eager_tensor_pyobject_ptr)) {
+      status->status = tensorflow::errors::InvalidArgument(
+          "The argument to `to_dlpack` must be a TF tensor, not Python object");
+      tensorflow::MaybeRaiseRegisteredFromTFStatus(status.get());
+    }
+
+    TFE_TensorHandle* thandle = EagerTensor_Handle(eager_tensor_pyobject_ptr);
     void* dlm_ptr = tensorflow::TFE_HandleToDLPack(thandle, status.get());
     tensorflow::MaybeRaiseRegisteredFromTFStatus(status.get());
 

programming_language: C++