I found one good article - Syzkaller + Kernel function fail-injection(https://github.com/hardenedlinux/Debian-GNU-Linux-Profiles/blob/master/docs/harbian_qa/fuzz_testing/syz_kfun_finject.md). As I know, the kernel fault-injection framework provides one option - fail-function which could modify the return value of specific functions. Why do not we use this option? This could also achieve the goal somehow. If I misunderstand something, please let me know.