Added fuzzer for frontend dockerfile parser

Signed-off-by: AdamKorcz <[email protected]>

Makefile

@@ -18,6 +18,9 @@ clean: FORCE
 test:
 	./hack/test integration gateway dockerfile
 
+fuzz:
+	./hack/fuzz
+
 lint:
 	./hack/lint
 

hack/dockerfiles/fuzz.Dockerfile

@@ -0,0 +1,17 @@
+FROM ubuntu:20.04
+ENV DEBIAN_FRONTEND=noninteractive 
+RUN apt-get update && apt-get upgrade -y
+RUN apt-get install wget git software-properties-common build-essential -y
+RUN wget https://golang.org/dl/go1.14.9.linux-amd64.tar.gz
+RUN tar -xvf go1.14.9.linux-amd64.tar.gz
+RUN mv go /usr/local
+
+RUN mkdir /root/src
+ENV GOPATH /root/go
+ENV GOROOT /usr/local/go
+ENV PATH $PATH:/usr/local/go/bin
+
+RUN go get github.com/moby/buildkit
+RUN go get -u github.com/dvyukov/go-fuzz/go-fuzz github.com/dvyukov/go-fuzz/go-fuzz-build
+COPY fuzz.go /go/src/github.com/moby/buildkit/frontend/dockerfiles/parser/
+RUN cd /go/src/github.com/moby/buildkit/frontend/dockerfiles/parser && $GOPATH/bin/go-fuzz-build && $GOPATH/bin/go-fuzz

hack/fuzz

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+
+cp util/testutil/fuzz/fuzz.go hack/dockerfiles/
+
+cd hack/dockerfiles && sudo docker build -f fuzz.Dockerfile .

util/testutil/fuzz/fuzz.go

@@ -0,0 +1,14 @@
+package fuzz
+
+import (
+	"bytes"
+	"github.com/moby/buildkit/frontend/dockerfile/parser"
+)
+
+func Fuzz(data []byte) int {
+	_, err := parser.Parse(bytes.NewReader(data))
+	if err != nil {
+		return 0
+	}
+	return 1
+}