# PoC: JIT Unpickler numel×itemsize Integer Overflow → Heap Buffer Overflow

**Vulnerability:** `torch/csrc/jit/serialization/unpickler.cpp:583` — `numel * dtype.itemsize()` integer overflow causes undersized storage allocation, leading to heap OOB read/write when loading a crafted TorchScript model.

## Files

- `poc_jit_numel_overflow.py` — Full PoC (creates crafted model, demonstrates OOB read + write crash)
- `overflow_model.pt` — Pre-built crafted TorchScript model

## Quick Start

```bash
pip install torch
python poc_jit_numel_overflow.py
```

## Expected Output

- Heap OOB Read: 16,380 bytes leaked beyond 4-byte buffer
- Heap OOB Write: `w.fill_(0)` crashes with SIGSEGV (heap corruption)