From 522265bdd06a15cf3b07fb5a2fe2a14cdabb9a1a Mon Sep 17 00:00:00 2001
From: Bryan Bernhart <bryan.bernhart@intel.com>
Date: Thu, 17 Sep 2026 13:47:48 -0700
Subject: [PATCH] Fix OOB read in InferenceContextImpl::getInputData when a
 trailing optional input is omitted

'Pads' on ConvTransposeWithDynamicPads is schema-optional, so a node can
validly supply only [X, W]. InferenceContextImpl::getInputData (graph.cc)
indexed node_.InputDefs() by the ONNX input index without checking it
against InputDefs().size(), so shape inference on such a node read past
the end of the vector. Add the same bounds check already used by
DataPropagationContextImpl::getInputData.
---
 onnxruntime/core/graph/graph.cc               |  6 +++++
 .../conv_transpose_with_dynamic_pads_test.cc  | 22 +++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/onnxruntime/core/graph/graph.cc b/onnxruntime/core/graph/graph.cc
index 257669c979bf1..90a680e19fe22 100644
--- a/onnxruntime/core/graph/graph.cc
+++ b/onnxruntime/core/graph/graph.cc
@@ -2748,6 +2748,12 @@ class InferenceContextImpl : public ONNX_NAMESPACE::InferenceContext {
   }
 
   const TensorProto* getInputData(size_t index) const override {
+    // A schema-optional input that's omitted (not even an empty placeholder) shrinks InputDefs(),
+    // so callers can pass an index the node doesn't actually have.
+    if (index >= getNumInputs()) {
+      return nullptr;
+    }
+
     auto def = node_.InputDefs()[index];
     if (!def)
       return nullptr;
diff --git a/onnxruntime/test/contrib_ops/conv_transpose_with_dynamic_pads_test.cc b/onnxruntime/test/contrib_ops/conv_transpose_with_dynamic_pads_test.cc
index 345a143d5b87c..b88985c8a2d42 100644
--- a/onnxruntime/test/contrib_ops/conv_transpose_with_dynamic_pads_test.cc
+++ b/onnxruntime/test/contrib_ops/conv_transpose_with_dynamic_pads_test.cc
@@ -2,7 +2,11 @@
 // Licensed under the MIT License.
 
 #include "gtest/gtest.h"
+#include "core/graph/model.h"
 #include "test/providers/provider_test_utils.h"
+#include "test/test_environment.h"
+#include "test/unittest_util/graph_transform_test_builder.h"
+#include "test/util/include/asserts.h"
 #include "default_providers.h"
 
 namespace onnxruntime {
@@ -147,5 +151,23 @@ TEST(ContribOpTest, ConvTransposeWithDynamicPads_NegativePads_Dml) {
 }
 #endif  // USE_DML
 
+// 'Pads' is schema-optional; a node may validly supply only X and W. Shape inference must not
+// index past the end of InputDefs() when reading the omitted Pads input.
+TEST(ContribOpTest, ConvTransposeWithDynamicPads_PadsOmitted_ShapeInferenceOnly) {
+  std::unordered_map<std::string, int> domain_to_version{{kOnnxDomain, 17}, {kMSDomain, 1}};
+  Model model("conv_transpose_with_dynamic_pads_pads_omitted", /*is_onnx_domain_only=*/false, ModelMetaData(),
+              PathString(), IOnnxRuntimeOpSchemaRegistryList(), domain_to_version, {},
+              DefaultLoggingManager().DefaultLogger());
+
+  ModelTestBuilder builder(model.MainGraph());
+  NodeArg* x = builder.MakeInput<float>(std::vector<int64_t>{1, 1, 3, 3});
+  NodeArg* w = builder.MakeInput<float>(std::vector<int64_t>{1, 1, 3, 3});
+  NodeArg* y = builder.MakeOutput();
+  builder.AddNode("ConvTransposeWithDynamicPads", {x, w}, {y}, kMSDomain);
+  builder.SetGraphOutputs();
+
+  ASSERT_STATUS_OK(model.MainGraph().Resolve());
+}
+
 }  // namespace test
 }  // namespace onnxruntime