Fix out-of-bounds read in CropBase: validate scale attribute length (microsoft#28399)

### Description

`CropBase::ValidateInput` guarded `scale_[0]`/`scale_[1]` access with
`!scale_.empty()` but never enforced `scale_.size() == 2`. A malformed
model with a wrong-length `scale` attribute (e.g. 1 element) causes an
out-of-bounds read in both validation and compute paths.

**Changes:**
- **`contrib_ops/cpu/crop.h`** — inside the `!scale_.empty()` branch,
return `INVALID_ARGUMENT` early if `scale_.size() != 2` with a
descriptive message before any indexing occurs. `Compute` is protected
transitively since it calls `ValidateInput` first.
- **`test/contrib_ops/crop_op_test.cc`** — added
`Crop_Invalid_Scale_Size` test: passes a 1-element `scale` attribute and
asserts the expected error is returned.

### Motivation and Context

`scale_` is a user-supplied attribute read directly from the model.
Without length validation a malformed model can trigger undefined
behavior (out-of-bounds vector read) in both the CPU and CUDA `Crop`
kernels (CUDA inherits `CropBase`).

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: tianleiwu <30328909+tianleiwu@users.noreply.github.com>
Co-authored-by: Tianlei Wu <tlwu@microsoft.com>

Author: Copilot

onnxruntime/contrib_ops/cpu/crop.h

@@ -53,6 +53,11 @@ class CropBase {
 
     // scale = (height, width)
     if (!scale_.empty()) {
+      if (scale_.size() != 2) {
+        return ORT_MAKE_STATUS(ONNXRUNTIME, INVALID_ARGUMENT,
+                               "Attribute scale needs to be specified with two elements (height, width), got ",
+                               scale_.size());
+      }
       int64_t bottomLimit = topBorder + scale_[0];
       int64_t rightLimit = leftBorder + scale_[1];
 

onnxruntime/test/contrib_ops/crop_op_test.cc

@@ -3,6 +3,7 @@
 
 #include "gtest/gtest.h"
 #include "test/providers/provider_test_utils.h"
+#include "test/util/include/default_providers.h"
 
 namespace onnxruntime {
 namespace test {
@@ -30,5 +31,24 @@ TEST(CropOpTest, Crop_Scale) {
   test.Run(OpTester::ExpectResult::kExpectSuccess, "", {kTensorrtExecutionProvider});
 }
 
+TEST(CropOpTest, Crop_Invalid_Scale_Size) {
+  OpTester test("Crop", 1, onnxruntime::kOnnxDomain);
+  test.AddInput<float>("x", {1, 1, 4, 4}, {1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0});
+
+  std::vector<int64_t> border{1, 1, 1, 1};
+  test.AddAttribute("border", border);
+
+  std::vector<int64_t> scale{2};  // invalid: must be exactly 2 elements
+  test.AddAttribute("scale", scale);
+
+  test.AddOutput<float>("y", {1, 1, 2, 2}, {6.0, 7.0, 10.0, 11.0});
+
+  std::vector<std::unique_ptr<IExecutionProvider>> execution_providers;
+  execution_providers.push_back(DefaultCpuExecutionProvider());
+  test.Run(OpTester::ExpectResult::kExpectFailure,
+           "Attribute scale needs to be specified with two elements (height, width), got 1",
+           {}, nullptr, &execution_providers);
+}
+
 }  // namespace test
 }  // namespace onnxruntime