Train in Vain: Functionality-Preserving Poisoning to Prevent Unauthorized Use of Code Datasets

Fuente: arXiv
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Main Authors: Xiao, Yuan, Wang, Jiaming, Chen, Yuchen, Song, Wei, Sun, Jun, Ma, Shiqing, Mu, Yanzhou, Zhai, Juan, Fang, Chunrong, Dong, Jin Song, Chen, Zhenyu
Format: Preprint
Published: 2026
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author Xiao, Yuan
Wang, Jiaming
Chen, Yuchen
Song, Wei
Sun, Jun
Ma, Shiqing
Mu, Yanzhou
Zhai, Juan
Fang, Chunrong
Dong, Jin Song
Chen, Zhenyu
author_facet Xiao, Yuan
Wang, Jiaming
Chen, Yuchen
Song, Wei
Sun, Jun
Ma, Shiqing
Mu, Yanzhou
Zhai, Juan
Fang, Chunrong
Dong, Jin Song
Chen, Zhenyu
contents The widespread availability of large-scale code datasets has accelerated the development of code large language models (CodeLLMs), raising concerns about unauthorized dataset usage. Dataset poisoning offers a proactive defense by reducing the utility of such unauthorized training. However, existing poisoning methods often require full dataset poisoning and introduce transformations that break code compilability. In this paper, we introduce FunPoison, a functionality-preserving poisoning approach that injects short, compilable weak-use fragments into executed code paths. FunPoison leverages reusable statement-level templates with automatic repair and conservative safety checking to ensure side-effect freedom, while a type-aware synthesis module suppresses static analysis warnings and enhances stealth. Extensive experiments show that FunPoison achieves effective poisoning by contaminating only 10% of the dataset, while maintaining 100% compilability and functional correctness, and remains robust against various advanced code sanitization techniques.
format Preprint
id arxiv_https___arxiv_org_abs_2604_22291
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Train in Vain: Functionality-Preserving Poisoning to Prevent Unauthorized Use of Code Datasets
Xiao, Yuan
Wang, Jiaming
Chen, Yuchen
Song, Wei
Sun, Jun
Ma, Shiqing
Mu, Yanzhou
Zhai, Juan
Fang, Chunrong
Dong, Jin Song
Chen, Zhenyu
Cryptography and Security
Software Engineering
The widespread availability of large-scale code datasets has accelerated the development of code large language models (CodeLLMs), raising concerns about unauthorized dataset usage. Dataset poisoning offers a proactive defense by reducing the utility of such unauthorized training. However, existing poisoning methods often require full dataset poisoning and introduce transformations that break code compilability. In this paper, we introduce FunPoison, a functionality-preserving poisoning approach that injects short, compilable weak-use fragments into executed code paths. FunPoison leverages reusable statement-level templates with automatic repair and conservative safety checking to ensure side-effect freedom, while a type-aware synthesis module suppresses static analysis warnings and enhances stealth. Extensive experiments show that FunPoison achieves effective poisoning by contaminating only 10% of the dataset, while maintaining 100% compilability and functional correctness, and remains robust against various advanced code sanitization techniques.
title Train in Vain: Functionality-Preserving Poisoning to Prevent Unauthorized Use of Code Datasets
topic Cryptography and Security
Software Engineering
url https://arxiv.org/abs/2604.22291