From 90be5436cb8780acd4c8d73a8ce9fc8e33b7b437 Mon Sep 17 00:00:00 2001
From: Marc Greisen <mgreisen@microsoft.com>
Date: Wed, 18 Oct 2023 16:52:09 -0700
Subject: [PATCH] Add fuzzer for coverage allowlist parse function (#3580)

---
 src/agent/coverage/fuzz/Cargo.lock            | 31 +++++++++++++++++++
 src/agent/coverage/fuzz/Cargo.toml            |  7 +++++
 .../fuzz_target_allowlist_parse.rs            | 12 +++++++
 3 files changed, 50 insertions(+)
 create mode 100644 src/agent/coverage/fuzz/fuzz_targets/fuzz_target_allowlist_parse.rs

diff --git a/src/agent/coverage/fuzz/Cargo.lock b/src/agent/coverage/fuzz/Cargo.lock
index 6096b84473..bbad571079 100644
--- a/src/agent/coverage/fuzz/Cargo.lock
+++ b/src/agent/coverage/fuzz/Cargo.lock
@@ -145,6 +145,7 @@ dependencies = [
  "log",
  "nix",
  "pete",
+ "process_control",
  "procfs",
  "regex",
  "symbolic",
@@ -805,6 +806,17 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "process_control"
+version = "4.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "32e056a69288d0a211f4c74c48391c6eb86e714fdcb9dc58a9f34302da9c20bf"
+dependencies = [
+ "libc",
+ "signal-hook",
+ "windows-sys 0.48.0",
+]
+
 [[package]]
 name = "procfs"
 version = "0.15.1"
@@ -1012,6 +1024,25 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "signal-hook"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8621587d4798caf8eb44879d42e56b9a93ea5dcd315a6487c357130095b62801"
+dependencies = [
+ "libc",
+ "signal-hook-registry",
+]
+
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8229b473baa5980ac72ef434c4415e70c4b5e71b423043adb4ba059f89c99a1"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "siphasher"
 version = "0.3.10"
diff --git a/src/agent/coverage/fuzz/Cargo.toml b/src/agent/coverage/fuzz/Cargo.toml
index 6f23f1b7a0..eef71b5fad 100644
--- a/src/agent/coverage/fuzz/Cargo.toml
+++ b/src/agent/coverage/fuzz/Cargo.toml
@@ -28,3 +28,10 @@ name = "fuzz_target_record_coverage"
 path = "fuzz_targets/fuzz_target_record_coverage.rs"
 test = false
 doc = false
+
+[[bin]]
+name = "fuzz_target_allowlist_parse"
+path = "fuzz_targets/fuzz_target_allowlist_parse.rs"
+test = false
+doc = false
+
diff --git a/src/agent/coverage/fuzz/fuzz_targets/fuzz_target_allowlist_parse.rs b/src/agent/coverage/fuzz/fuzz_targets/fuzz_target_allowlist_parse.rs
new file mode 100644
index 0000000000..dd27a8b313
--- /dev/null
+++ b/src/agent/coverage/fuzz/fuzz_targets/fuzz_target_allowlist_parse.rs
@@ -0,0 +1,12 @@
+#![no_main]
+
+use libfuzzer_sys::fuzz_target;
+use coverage::allowlist::AllowList;
+
+fuzz_target!(|data: &[u8]| {
+    // fuzzed code goes here
+    if let Ok(s) = std::str::from_utf8(data) 
+    {
+        let _ = AllowList::parse(s);
+    }
+});