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| license: other |
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| # ExecuTorch .ptd Null-Pointer Dereference PoC |
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| Security research PoC for Huntr MFV submission. |
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| **Vulnerability**: Missing FlatBuffer verifier + null pointer dereference in `FlatTensorDataMap::load()` when processing malicious `.ptd` external weight files. |
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| **Affected**: pytorch/executorch (latest main, commit 6018283) |
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| **Component**: `extension/flat_tensor/flat_tensor_data_map.cpp:114-125` |
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| ## Files |
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| - `poc_null_sizes.ptd` — TensorLayout present but `sizes` field absent → `sizes()` returns nullptr → SIGSEGV (exit 134) |
| - `poc_null_tl.ptd` — NamedData with no `tensor_layout` → `tensor_layout()` returns nullptr → SIGSEGV (exit 134) |
| - `reproduce.py` — Script to regenerate PoC files |
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| ## Root Cause |
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| `FlatTensorDataMap::load()` calls `GetFlatTensor()` without running `VerifyFlatTensorBuffer()`. The subsequent `create_tensor_layout()` dereferences `tensor_layout->sizes()` without null-checking this optional flatbuffer field. |
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