4d8b566a87
* Add libfuzzer example for window with ASAN * Fix formatting * Add link * Fix cpp format * Skip windows fuzzers * Fix format * Fix testing fuzzer * Fix taks name Co-authored-by: Dongjia "toka" Zhang <tokazerkje@outlook.com> Co-authored-by: Andrea Fioraldi <andreafioraldi@gmail.com> Co-authored-by: Dominik Maier <domenukk@gmail.com>
50 lines
1.8 KiB
Markdown
50 lines
1.8 KiB
Markdown
# LibFuzzer Example for Windows with ASAN
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This folder contains an example fuzzer for Windows which also uses ASAN.
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We are initializing LibAFL to be compatible with ASAN.
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## Setup
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We are currently using Clang on Windows. Make sure to install Clang through the Visual Studio installer.
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We recommend using Powershell and enabling the Visual Studio environment using this script:
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```powershell
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Push-Location "C:\Program Files\Microsoft Visual Studio\2022\Professional\VC\Auxiliary\Build\"
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& "C:\\Windows\System32\cmd.exe" /c "vcvars64.bat & set" |
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ForEach-Object {
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if ($_ -match "=") {
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$v = $_.split("=", 2); set-item -force -path "ENV:\$($v[0])" -value "$($v[1])"
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}
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}
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Pop-Location
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Write-Host "`nVisual Studio 2022 Command Prompt variables set." -ForegroundColor Yellow
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````
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After that clang should be available in the PATH.
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## Build
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To build the fuzzer and link against the `harness.cpp` in this example run:
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```
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cargo make fuzzer
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```
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## Running
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```
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.\libfuzzer_windows_asan.exe
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```
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## Note on MSVC
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The MSVC compiler (`cl.exe`) will work in the future. Currently, it is blocked because of a [bug](https://developercommunity.visualstudio.com/t/__sanitizer_cov_trace_pc_guard_init-neve/10218995) with coverage.
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### Note on ASAN
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Using ASAN on Windows with MSVC is not trivial as of 2022. Depending on the harness and fuzzing target, the required compilation flags differ. Most notably, the usage of `/MT` and `/MD` for the CRT is important. All compilation artifacts should use the same config for the CRT (either all `/MT` or all `/MD`). [Rust uses as of 2022](https://rust-lang.github.io/rfcs/1721-crt-static.html) `/MD` as default. So compile everything with `/MD`.
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Depending on the linking mode different ASAN libraries get linked. Definitely read [this](https://devblogs.microsoft.com/cppblog/addresssanitizer-asan-for-windows-with-msvc/) blog post by Microsoft.
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