Clone this repo:


  1. a0d9129 [Reland] Remove absolute paths from build files by Tom Anderson · 9 days ago master
  2. 6a4413a Revert "Remove absolute paths from build files" by John Budorick · 9 days ago
  3. 6620e13 Remove absolute paths from build files by Tom Anderson · 9 days ago
  4. 9592019 Teach about GN groups. by Lei Zhang · 2 weeks ago
  5. fbfb584 Change fuzzer_test GN template to pass full paths for deps. by Lei Zhang · 3 weeks ago

libFuzzer in Chromium

go/libfuzzer-chromium (Googler only)

This directory contains integration between libFuzzer and Chromium. LibFuzzer is an in-process coverage-driven evolutionary fuzzing engine. It helps engineers to uncover potential security & stability problems earlier.

Requirements: libFuzzer in Chromium is supported with Linux and Mac only.

Integration Status

Fuzzer tests are well-integrated with Chromium build system and distributed ClusterFuzz fuzzing system. Cover bug:


  • Getting Started Guide walks you through all the steps necessary to create your fuzz target and submit it to ClusterFuzz.
  • Efficient Fuzzer Guide explains how to measure fuzz target effectiveness and ways to improve it.
  • Guide to libprotobuf-mutator walks through the steps necessary to create a fuzz target that expects a protobuf as input (instead of a byte stream). In addition to fuzzing code that accepts protobufs, it can be used to fuzz code that requires multiple mutated inputs, or to generate inputs defined by a grammar.
  • ClusterFuzz Integration describes integration between ClusterFuzz and libFuzzer.
  • Reproducing contains information on how to reproduce bugs reported by ClusterFuzz.
  • Reference contains detailed references for different integration parts.


  • ClusterFuzz Bugs - issues found and automatically filed by ClusterFuzz.
  • Manual Bugs - issues that were filed manually after running fuzz targets.
  • Pdfium Bugs - bugs found in pdfium by manual fuzzing.
  • OSS Trophies - bugs found with libFuzzer in open-source projects.

Blog Posts

Project Links