Add size check on partial_ops x input vector (#34595)

### Details:
- *Add input count validation in partial_ops() to prevent out-of-bounds
access*

### Tickets:
 - *CVS-182184*

Author: mangguo321

src/frontends/paddle/src/op/partial_ops.hpp

@@ -12,6 +12,7 @@ namespace op {
 
 NamedOutputs partial_ops(const NodeContext& node, const std::string type) {
     auto x = node.get_ng_inputs("X");
+    PADDLE_OP_CHECK(node, x.size() == 2, "partial_ops requires exactly 2 inputs in X.");
     const auto start_index = node.get_attribute<int>("start_index");
     const auto length = node.get_attribute<int>("length");
     PADDLE_OP_CHECK(node, x[0].get_partial_shape().rank().get_length() == 2, "partial ops only support 2-D Tensor");

src/frontends/paddle/tests/read_paddle_model_test.cpp

@@ -307,3 +307,18 @@ TEST(Paddle_Reader_Tests, ImportBasicModelToCoreWstring) {
     ASSERT_TRUE(res.valid) << res.message;
 }
 #endif
+
+TEST(Paddle_Reader_Tests, LoadModelWithPartialOpsInsufficientInputs) {
+    auto model =
+        FrontEndTestUtils::make_model_path(std::string(TEST_PADDLE_MODELS_DIRNAME) + "partial_sum_oob/partial_sum_oob" +
+                                           std::string(TEST_PADDLE_MODEL_EXT));
+
+    ov::Core core;
+    try {
+        core.read_model(model);
+        FAIL() << "Expected load to fail due to insufficient X inputs for partial_sum";
+    } catch (const std::exception& ex) {
+        const std::string msg = ex.what();
+        ASSERT_NE(msg.find("partial_ops requires exactly 2 inputs in X."), std::string::npos) << msg;
+    }
+}

src/frontends/paddle/tests/test_models/gen_scripts/generate_partial_sum.py

@@ -5,11 +5,48 @@
 # partial_sum paddle model generator
 #
 import numpy as np
+import os
 from save_model import saveModel
 import paddle
 import sys
 
 
+def _get_framework_pb2():
+    try:
+        from paddle.fluid.proto import framework_pb2
+        return framework_pb2
+    except Exception:
+        pass
+    try:
+        from paddle.base.proto import framework_pb2
+        return framework_pb2
+    except Exception:
+        from paddle.framework.proto import framework_pb2
+        return framework_pb2
+
+
+def _corrupt_partial_sum_inputs(model_path: str):
+    framework_pb2 = _get_framework_pb2()
+    prog = framework_pb2.ProgramDesc()
+    with open(model_path, "rb") as f:
+        prog.ParseFromString(f.read())
+
+    modified = False
+    for block in prog.blocks:
+        for op in block.ops:
+            if op.type == "partial_sum":
+                for inp in op.inputs:
+                    if inp.parameter == "X" and len(inp.arguments) > 1:
+                        del inp.arguments[1:]
+                        modified = True
+
+    if not modified:
+        raise RuntimeError("Failed to modify partial_sum X inputs in model")
+
+    with open(model_path, "wb") as f:
+        f.write(prog.SerializeToString())
+
+
 def partial_sum(name: str, x, y, start_index=0, length=-1):
     paddle.enable_static()
 
@@ -64,5 +101,12 @@ def main():
     y = np.random.randint(-10, 10, [8, 10]).astype(dtype)
     partial_sum("partial_sum_3", x, y, start_index=1, length=5)
 
+    dtype = 'float32'
+    x = np.random.randn(4, 8).astype(dtype)
+    y = np.random.randn(4, 8).astype(dtype)
+    partial_sum("partial_sum_oob", x, y, start_index=0, length=4)
+    model_path = os.path.join(sys.argv[1], "partial_sum_oob", "partial_sum_oob.pdmodel")
+    _corrupt_partial_sum_inputs(model_path)
+
 if __name__ == "__main__":
     main()