replace uses of os/exec with golang.org/x/sys/execabs

Go 1.15.7 contained a security fix for CVE-2021-3115, which allowed arbitrary
code to be executed at build time when using cgo on Windows. This issue also
affects Unix users who have “.” listed explicitly in their PATH and are running
“go get” outside of a module or with module mode disabled.

This issue is not limited to the go command itself, and can also affect binaries
that use `os.Command`, `os.LookPath`, etc.

From the related blogpost (ttps://blog.golang.org/path-security):

> Are your own programs affected?
>
> If you use exec.LookPath or exec.Command in your own programs, you only need to
> be concerned if you (or your users) run your program in a directory with untrusted
> contents. If so, then a subprocess could be started using an executable from dot
> instead of from a system directory. (Again, using an executable from dot happens
> always on Windows and only with uncommon PATH settings on Unix.)
>
> If you are concerned, then we’ve published the more restricted variant of os/exec
> as golang.org/x/sys/execabs. You can use it in your program by simply replacing

This patch replaces all uses of `os/exec` with `golang.org/x/sys/execabs`. While
some uses of `os/exec` should not be problematic (e.g. part of tests), it is
probably good to be consistent, in case code gets moved around.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

archive/compression/compression.go

@@ -24,12 +24,12 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"os/exec"
 	"strconv"
 	"sync"
 
 	"github.com/containerd/containerd/log"
 	"github.com/klauspost/compress/zstd"
+	exec "golang.org/x/sys/execabs"
 )
 
 type (

archive/compression/compression_test.go

@@ -24,11 +24,12 @@ import (
 	"io/ioutil"
 	"math/rand"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"testing"
+
+	exec "golang.org/x/sys/execabs"
 )
 
 func TestMain(m *testing.M) {

archive/tar_test.go

@@ -27,7 +27,6 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"testing"
 	"time"
@@ -39,6 +38,7 @@ import (
 	"github.com/containerd/continuity/fs"
 	"github.com/containerd/continuity/fs/fstest"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 )
 
 const tarCmd = "tar"

cmd/containerd-shim/main_unix.go

@@ -27,7 +27,6 @@ import (
 	"io"
 	"net"
 	"os"
-	"os/exec"
 	"os/signal"
 	"runtime"
 	"runtime/debug"
@@ -48,6 +47,7 @@ import (
 	ptypes "github.com/gogo/protobuf/types"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
+	exec "golang.org/x/sys/execabs"
 	"golang.org/x/sys/unix"
 )
 

cmd/containerd/command/service_windows.go

@@ -21,7 +21,6 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"time"
 	"unsafe"
@@ -31,6 +30,7 @@ import (
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
+	exec "golang.org/x/sys/execabs"
 	"golang.org/x/sys/windows"
 	"golang.org/x/sys/windows/svc"
 	"golang.org/x/sys/windows/svc/debug"

cmd/ctr/commands/content/content.go

@@ -21,7 +21,6 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"strings"
 	"text/tabwriter"
 	"time"
@@ -35,6 +34,7 @@ import (
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
+	exec "golang.org/x/sys/execabs"
 )
 
 var (

contrib/apparmor/template.go

@@ -27,13 +27,13 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path"
 	"strconv"
 	"strings"
 	"text/template"
 
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 )
 
 // NOTE: This code is copied from <github.com/docker/docker/profiles/apparmor>.

contrib/fuzz/container_fuzzer.go

@@ -26,17 +26,18 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	fuzz "github.com/AdaLogics/go-fuzz-headers"
-	"github.com/containerd/containerd"
-	"github.com/containerd/containerd/oci"
-	"github.com/containerd/containerd/sys"
 	"io"
 	"io/ioutil"
 	"net/http"
 	"os"
-	"os/exec"
 	"strings"
 	"time"
+
+	fuzz "github.com/AdaLogics/go-fuzz-headers"
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/oci"
+	"github.com/containerd/containerd/sys"
+	exec "golang.org/x/sys/execabs"
 )
 
 var (

contrib/nvidia/nvidia.go

@@ -20,13 +20,13 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"os/exec"
 	"strconv"
 	"strings"
 
 	"github.com/containerd/containerd/containers"
 	"github.com/containerd/containerd/oci"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
+	exec "golang.org/x/sys/execabs"
 )
 
 // NvidiaCLI is the path to the Nvidia helper binary

diff/stream_unix.go

@@ -25,12 +25,12 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"os/exec"
 	"sync"
 
 	"github.com/gogo/protobuf/proto"
 	"github.com/gogo/protobuf/types"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 )
 
 // NewBinaryProcessor returns a binary processor for use with processing content streams

diff/stream_windows.go

@@ -23,7 +23,6 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"sync"
 
@@ -32,6 +31,7 @@ import (
 	"github.com/gogo/protobuf/types"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
+	exec "golang.org/x/sys/execabs"
 )
 
 const processorPipe = "STREAM_PROCESSOR_PIPE"

integration/client/client_test.go

@@ -24,7 +24,6 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"testing"
 	"time"
 
@@ -42,6 +41,7 @@ import (
 	"github.com/opencontainers/go-digest"
 	"github.com/opencontainers/image-spec/identity"
 	"github.com/sirupsen/logrus"
+	exec "golang.org/x/sys/execabs"
 )
 
 var (

integration/client/container_linux_test.go

@@ -23,7 +23,6 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
@@ -50,6 +49,7 @@ import (
 	"github.com/containerd/typeurl"
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 	"golang.org/x/sys/unix"
 )
 

integration/client/container_test.go

@@ -22,7 +22,6 @@ import (
 	"io"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path"
 	"runtime"
 	"strings"
@@ -33,18 +32,18 @@ import (
 	. "github.com/containerd/containerd"
 	"github.com/containerd/containerd/cio"
 	"github.com/containerd/containerd/containers"
+	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/namespaces"
 	"github.com/containerd/containerd/oci"
 	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/containerd/plugin"
 	_ "github.com/containerd/containerd/runtime"
 	"github.com/containerd/containerd/runtime/v2/runc/options"
-	"github.com/containerd/typeurl"
-	specs "github.com/opencontainers/runtime-spec/specs-go"
-
-	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/go-runc"
+	"github.com/containerd/typeurl"
 	gogotypes "github.com/gogo/protobuf/types"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	exec "golang.org/x/sys/execabs"
 )
 
 func empty() cio.Creator {

integration/client/daemon_config_linux_test.go

@@ -23,7 +23,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 	"syscall"
@@ -37,6 +36,7 @@ import (
 	"github.com/containerd/containerd/plugin"
 	"github.com/containerd/containerd/runtime/v2/runc/options"
 	srvconfig "github.com/containerd/containerd/services/server/config"
+	exec "golang.org/x/sys/execabs"
 )
 
 // the following nolint is for shutting up gometalinter on non-linux.

integration/client/daemon_test.go

@@ -19,12 +19,12 @@ package client
 import (
 	"context"
 	"io"
-	"os/exec"
 	"sync"
 	"syscall"
 
 	. "github.com/containerd/containerd"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 )
 
 type daemon struct {

integration/image_load_test.go

@@ -19,13 +19,13 @@ package integration
 import (
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	exec "golang.org/x/sys/execabs"
 	runtime "k8s.io/cri-api/pkg/apis/runtime/v1"
 )
 

integration/main_test.go

@@ -22,7 +22,6 @@ import (
 	"flag"
 	"fmt"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -31,19 +30,19 @@ import (
 
 	"github.com/containerd/containerd"
 	cri "github.com/containerd/containerd/integration/cri-api/pkg/apis"
-	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"google.golang.org/grpc"
-	runtime "k8s.io/cri-api/pkg/apis/runtime/v1"
-
 	"github.com/containerd/containerd/integration/remote"
 	dialer "github.com/containerd/containerd/integration/util"
 	criconfig "github.com/containerd/containerd/pkg/cri/config"
 	"github.com/containerd/containerd/pkg/cri/constants"
 	"github.com/containerd/containerd/pkg/cri/server"
 	"github.com/containerd/containerd/pkg/cri/util"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	exec "golang.org/x/sys/execabs"
+	"google.golang.org/grpc"
+	runtime "k8s.io/cri-api/pkg/apis/runtime/v1"
 )
 
 const (

integration/volume_copy_up_test.go

@@ -18,13 +18,13 @@ package integration
 
 import (
 	"fmt"
-	"os/exec"
 	goruntime "runtime"
 	"testing"
 	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	exec "golang.org/x/sys/execabs"
 )
 
 func TestVolumeCopyUp(t *testing.T) {

mount/lookup_linux_test.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -29,6 +28,7 @@ import (
 	// so we use continuity/testutil instead.
 	"github.com/containerd/continuity/testutil"
 	"github.com/containerd/continuity/testutil/loopback"
+	exec "golang.org/x/sys/execabs"
 	"gotest.tools/v3/assert"
 )
 

mount/mount_freebsd.go

@@ -18,10 +18,10 @@ package mount
 
 import (
 	"os"
-	"os/exec"
 	"time"
 
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 	"golang.org/x/sys/unix"
 )
 

mount/mount_linux.go

@@ -19,12 +19,12 @@ package mount
 import (
 	"fmt"
 	"os"
-	"os/exec"
 	"path"
 	"strings"
 	"time"
 
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 	"golang.org/x/sys/unix"
 )
 

mount/mount_linux_test.go

@@ -20,12 +20,12 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"reflect"
 	"testing"
 
 	"github.com/containerd/continuity/testutil"
+	exec "golang.org/x/sys/execabs"
 )
 
 func TestLongestCommonPrefix(t *testing.T) {