SecurityCipher
Home Blog About Us
Resources ▼
✅ Security Checklists Hub 🗺️ Penetration Testing Roadmap 🤖 OWASP Top 10 for LLM Applications 🧠 LLM AI Security Checklist 🛠️ Security Tools 🎯 Penetration Testing Tricks 📄 Secure Code Explain 📖 Vulnerability Explain ☁️ AWS Cloud Security Checklist
My Resume
Our ServicesServices
New On-Call Drive Drive the neon city, jack in, and clear security tickets Play now →
← Security Tools View on GitHub

razzer

A Kernel fuzzer focusing on race bugs

Razzer: Finding kernel race bugs through fuzzing

Environment setup

$ source scripts/envsetup.sh

scripts/envsetup.sh sets up necessary environment variables. One should select the kernel version during environment setup, for example, v4.17.

Install

Initialize kernels_repo submodule

Kernel source codes used in this project are in the other reprository which is included as a submodule. To initialize the submodule one should execute git submodule update command as a follow.

$ git submodule update --init --depth=1 kernels_repo

Dependencies

$ sudo apt install zlib libglib-dev python-setuptools quilt libssl-dev dwarfdump

Install toolchains / tools

$ scripts/install.sh

scripts/install.sh then installs all the rest necessary toolchains and tools.

Static analysis

The Razzer's static analysis is based on the LLVM toolchain and the SVF static analysis tool. See documents in docs/static-analysis.md.

Fuzzing

Razzer's two-phases fuzzing is based on Syzkaller. The deterministic scheduler is implemented using QEMU/KVM. See documents in docs/fuzzing.md.

Paper

Razzer: Finding Kernel Race Bugs through Fuzzing (IEEE S&P 2019)

Trophies

  • KASAN: slab-out-of-bounds write in tty_insert_flip_string_flag
  • WARNING in __static_key_slow_dec
  • Kernel BUG at net/packet/af_packet.c:LINE!
  • WARNING in refcount_dec
  • unable to handle kernel paging request in snd_seq_oss_readq_puts
  • KASAN: use-after-free Read in loopback_active_get
  • KASAN: null-ptr-deref Read in rds_ib_get_mr (assisted Syzkaller)
  • KASAN: use-after-free Read in nd_jump_root (discussed more in the linux security mailing list)
  • KASAN: use-after-free Read in link_path_walk (discussed in the linux security mailing list)
  • WARNING in ip_recv_error
  • KASAN: use-after-free Read in vhost_chr_write_iter
  • BUG: soft lockup in snd_virmidi_output_trigger (assisted Syzkaller)
  • KASAN: null-ptr-deref Read in smc_ioctl
  • KASAN: null-ptr-deref Write in binder_update_page_range
  • WARNING in port_delete
  • KASAN: null-ptr-deref in inode_permission (discussed in the linux security mailing list)

Contributors

  • Dae R. Jeong (threeearcat@gmail.com)
  • Kyungtae Kim (kim1798@purdue.edu)
  • Basavesh Ammanaghatta Shivakumar (bammanag@purdue.edu)
  • Byoungyoung Lee (byoungyoung@snu.ac.kr)
  • Insik Shin (insik.shin@cs.kaist.ac.kr)

Penetration Testing Services

penetration Testing Services

Web Application Security Quiz

Web Application Security Quiz

Daily Bug Bounty Writeups - Twitter

Daily Bug Bounty Writeups

Download our Latest Android Application

Guide for Penetration Testing

Daily Bug Bounty Writeups - Telegram

Daily Bug Bounty Writeups

Author

Piyush
Senior Product Security Engineer

Ethical Hacker || Penetration Tester || Gamer || Blogger || Product Security Engineer || AI Security

READ ARTICLE

Donate

Buy me a Coffee

Recent Posts

  • Cloud Misconfig Bounty Hunting in 2026: Open Buckets, Firebase, and Secrets
    Cloud Misconfig Bounty Hunting in 2026: Open Buckets, Firebase, and Secrets
    September 8, 2026/
    0 Comments
  • DevSecOps From Laptop to Production: A Practical Security Pipeline Guide
    DevSecOps From Laptop to Production: A Practical Security Pipeline Guide
    August 27, 2026/
    0 Comments
  • The CVE Flood Is a Lie: How to Hunt When AI Dumps 36% More Bugs But Exploitation Only Grows 10%
    The CVE Flood Is a Lie: How to Hunt When AI Dumps 36% More Bugs But Exploitation Only Grows 10%
    August 25, 2026/
    0 Comments

Follow Us

SecurityCipher

Practical security guides, vulnerability deep-dives, and hands-on resources for bug bounty hunters and penetration testers.

Useful Links

  • Security Checklists
  • Cybersecurity Jobs
  • Blogs
  • About
  • Contact
© 2026 SecurityCipher. All rights reserved. Privacy Policies · Terms & Conditions