Fuzzing: Add archive fuzzer

Signed-off-by: AdamKorcz <adam@adalogics.com>

contrib/fuzz/archive_fuzzer.go

@@ -0,0 +1,52 @@
+// +build gofuzz
+
+/*
+   Copyright The containerd Authors.
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+       http://www.apache.org/licenses/LICENSE-2.0
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package fuzz
+
+import (
+	"bytes"
+	"context"
+	"io/ioutil"
+	"os"
+
+	fuzz "github.com/AdaLogics/go-fuzz-headers"
+
+	"github.com/containerd/containerd/archive"
+)
+
+// FuzzApply implements a fuzzer that applies
+// a fuzzed tar archive on a directory
+func FuzzApply(data []byte) int {
+	f := fuzz.NewConsumer(data)
+	iters, err := f.GetInt()
+	if err != nil {
+		return 0
+	}
+	maxIters := 20
+	tmpDir, err := ioutil.TempDir("", "prefix-test")
+	if err != nil {
+		return 0
+	}
+	defer os.RemoveAll(tmpDir)
+	for i := 0; i < iters%maxIters; i++ {
+		rBytes, err := f.TarBytes()
+		if err != nil {
+			return 0
+		}
+		r := bytes.NewReader(rBytes)
+		_, _ = archive.Apply(context.Background(), tmpDir, r)
+	}
+	return 1
+}

contrib/fuzz/oss_fuzz_build.sh

@@ -17,9 +17,10 @@
 cd "$(dirname "${BASH_SOURCE[0]}")"
 cd ../../
 
-compile_go_fuzzer github.com/containerd/containerd/contrib/fuzz FuzzFiltersParse fuzz_filters_parse
-compile_go_fuzzer github.com/containerd/containerd/contrib/fuzz FuzzPlatformsParse fuzz_platforms_parse
-
+# Don't move docker_fuzzer.go back into contrib/fuzz
 mv contrib/fuzz/docker_fuzzer.go remotes/docker/
 compile_go_fuzzer github.com/containerd/containerd/remotes/docker FuzzFetcher fuzz_fetcher
-mv remotes/docker/docker_fuzzer.go contrib/fuzz/
+
+compile_go_fuzzer github.com/containerd/containerd/contrib/fuzz FuzzFiltersParse fuzz_filters_parse
+compile_go_fuzzer github.com/containerd/containerd/contrib/fuzz FuzzPlatformsParse fuzz_platforms_parse
+compile_go_fuzzer github.com/containerd/containerd/contrib/fuzz FuzzApply fuzz_apply