[BUG] The pass "adjust_slice_and_matmul" causes crash (malloc_error_break)

[BUG] The pass "adjust_slice_and_matmul" causes crash (malloc_error_break)

Issue
Running the single pass adjust_slice_and_matmul with onnxoptimizer 0.4.2 may cause crash. Details are provided to reproduce the issue with oracle inputs.

Environment

• Ubuntu 20.04
• Python 3.10
• onnx==1.19.0
• onnxruntime==1.23.2
• onnxoptimizer==0.4.2 (latest)

Repro steps (run from this folder)

1. Download and unzip the attached archive, then cd into the extracted directory

tar -xzvf adjust_slice_and_matmul_repro.tar.gz
cd adjust_slice_and_matmul_repro

2. Create a Python environment (Python 3.10) and install dependencies:

python3 -m venv .venv
source .venv/bin/activate
pip install -U pip
pip install -r requirements.txt

3. Optimize a case with only adjust_slice_and_matmul (writes model.opt.onnx next to model.onnx):

• python optimize_model.py --case ./case_02937_seed43509122

1. Differential test original vs optimized outputs using stored oracle inputs:

• python diff_test.py --case ./case_02937_seed43509122

Observed results
Crash : case_02937_seed43509122 (malloc error during diff run; see notes below).

Expected
adjust_slice_and_matmul should be semantics-preserving and should not cause crash when optimizing models.

Differential Test Output Details

1. case_02937_seed43509122: diff test aborted with malloc checksum error after, no comparison result produced.

Python(21317,0x1f992e0c0) malloc: Incorrect checksum for freed object 0x127037200: probably modified after being freed.
Corrupt value: 0x42b444884512460f
Python(21317,0x1f992e0c0) malloc: *** set a breakpoint in malloc_error_break to debug

Attachments

• README.md
• requirements.txt
• optimize_model.py (runs only adjust_slice_and_matmul and saves model.opt.onnx)
• diff_test.py (runs original and optimized with same oracle inputs)
• case_02937_seed43509122/ (original model and oracle inputs)

Start by reading README.md and running optimize_model.py followed by diff_test.py for case_02937_seed43509122 using requirements.txt. Compare the original and optimized model behavior and investigate the crash around the adjust_slice_and_matmul pass. Done means the case completes without malloc corruption and the pass remains semantics-preserving.