Fix path traversal in TensorRT EP RefitEngine (#29396)
## Summary
Fix a path traversal vulnerability in the TensorRT and NvTensorRTRTX
Execution Providers' `RefitEngine()` function. Path validation was
deliberately disabled at production call sites, allowing malicious ONNX
models to potentially read arbitrary files when weight-stripped engine
refitting is active.
## Problem
`RefitEngine()` accepted a `path_check` parameter that controlled
whether path traversal validation was performed. All non-EPContext call
sites passed `false`, completely bypassing security checks.
Additionally, the NvTensorRTRTX `onnx_ctx_model_helper.cc` had
**inverted** logic (`ep_context_model_path_.empty()` instead of
`!...empty()`), which disabled path checks when loading from files --
the exact case where validation is most needed.
An attacker could craft a malicious ONNX model with a traversal path in
the `ONNX_MODEL_FILENAME` attribute (e.g. `../../../etc/passwd`) to
cause the runtime to read arbitrary filesystem paths during engine
refitting.
## Fix
- **Remove the `path_check` parameter** from `RefitEngine()` in both
TensorRT EP and NvTensorRTRTX EP -- path validation via
`ValidateExternalDataPathFromDir()` is now unconditional
- **At internal call sites**, extract just the filename from
`model_path_` and derive the folder path so validation can verify
directory containment (`model_path_` is a full absolute path from
`graph.ModelPath()`, which would be rejected by the validator as-is)
- **Remove `make_secure_path_checks`** variable from both
`onnx_ctx_model_helper.cc` files (no longer needed since validation is
always on)
## Files Changed
- `onnxruntime/core/providers/tensorrt/tensorrt_execution_provider.h` --
remove `path_check` parameter
- `onnxruntime/core/providers/tensorrt/tensorrt_execution_provider.cc`
-- always validate, fix call sites
- `onnxruntime/core/providers/tensorrt/onnx_ctx_model_helper.cc` --
remove now-unused variable and argument
- `onnxruntime/core/providers/nv_tensorrt_rtx/nv_execution_provider.h`
-- remove `path_check` parameter
- `onnxruntime/core/providers/nv_tensorrt_rtx/nv_execution_provider.cc`
-- always validate, fix call site
- `onnxruntime/core/providers/nv_tensorrt_rtx/onnx_ctx_model_helper.cc`
-- remove inverted-logic variable and argument
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
