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) {

pkg/process/io.go

@@ -25,7 +25,6 @@ import (
 	"io"
 	"net/url"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"sync"
 	"sync/atomic"
@@ -39,6 +38,7 @@ import (
 	runc "github.com/containerd/go-runc"
 	"github.com/hashicorp/go-multierror"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 )
 
 const binaryIOProcTermTimeout = 12 * time.Second // Give logger process solid 10 seconds for cleanup

pkg/process/io_util.go

@@ -19,7 +19,8 @@ package process
 import (
 	"net/url"
 	"os"
-	"os/exec"
+
+	exec "golang.org/x/sys/execabs"
 )
 
 // NewBinaryCmd returns a Cmd to be used to start a logging binary.

runtime/v1/shim/client/client.go

@@ -26,7 +26,6 @@ import (
 	"io/ioutil"
 	"net"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strconv"
 	"strings"
@@ -34,12 +33,6 @@ import (
 	"syscall"
 	"time"
 
-	"golang.org/x/sys/unix"
-
-	"github.com/containerd/ttrpc"
-	"github.com/pkg/errors"
-	"github.com/sirupsen/logrus"
-
 	"github.com/containerd/containerd/events"
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/pkg/dialer"
@@ -47,7 +40,12 @@ import (
 	"github.com/containerd/containerd/runtime/v1/shim"
 	shimapi "github.com/containerd/containerd/runtime/v1/shim/v1"
 	"github.com/containerd/containerd/sys"
+	"github.com/containerd/ttrpc"
 	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"
 )
 
 var empty = &ptypes.Empty{}

runtime/v1/shim/client/client_linux.go

@@ -17,11 +17,11 @@
 package client
 
 import (
-	"os/exec"
 	"syscall"
 
 	"github.com/containerd/cgroups"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 )
 
 func getSysProcAttr() *syscall.SysProcAttr {

runtime/v1/shim/client/client_unix.go

@@ -20,8 +20,9 @@
 package client
 
 import (
-	"os/exec"
 	"syscall"
+
+	exec "golang.org/x/sys/execabs"
 )
 
 func getSysProcAttr() *syscall.SysProcAttr {

runtime/v2/runc/v1/service.go

@@ -23,7 +23,6 @@ import (
 	"context"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"sync"
 	"syscall"
@@ -50,6 +49,7 @@ 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"
 )
 

runtime/v2/runc/v2/service.go

@@ -24,7 +24,6 @@ import (
 	"encoding/json"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"sync"
 	"syscall"
@@ -54,6 +53,7 @@ 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"
 )
 

runtime/v2/shim/util.go

@@ -23,7 +23,6 @@ import (
 	"io/ioutil"
 	"net"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 	"sync"
@@ -33,6 +32,7 @@ import (
 	"github.com/gogo/protobuf/proto"
 	"github.com/gogo/protobuf/types"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 )
 
 var runtimePaths sync.Map
@@ -73,12 +73,9 @@ func Command(ctx context.Context, runtime, containerdAddress, containerdTTRPCAdd
 			if cmdPath, lerr = exec.LookPath(name); lerr != nil {
 				if eerr, ok := lerr.(*exec.Error); ok {
 					if eerr.Err == exec.ErrNotFound {
-						// LookPath only finds current directory matches based on
-						// the callers current directory but the caller is not
-						// likely in the same directory as the containerd
-						// executables. Instead match the calling binaries path
-						// (containerd) and see if they are side by side. If so
-						// execute the shim found there.
+						// Match the calling binaries (containerd) path and see
+						// if they are side by side. If so, execute the shim
+						// found there.
 						testPath := filepath.Join(filepath.Dir(self), name)
 						if _, serr := os.Stat(testPath); serr == nil {
 							cmdPath = testPath

snapshots/btrfs/btrfs_test.go

@@ -24,7 +24,6 @@ import (
 	"context"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -37,6 +36,7 @@ import (
 	"github.com/containerd/containerd/snapshots/testsuite"
 	"github.com/containerd/continuity/testutil/loopback"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 	"golang.org/x/sys/unix"
 )
 

snapshots/devmapper/blkdiscard/blkdiscard.go

@@ -19,7 +19,7 @@
 
 package blkdiscard
 
-import "os/exec"
+import exec "golang.org/x/sys/execabs"
 
 // Version returns the output of "blkdiscard --version"
 func Version() (string, error) {

snapshots/devmapper/dmsetup/dmsetup.go

@@ -25,12 +25,12 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"os/exec"
 	"strconv"
 	"strings"
 
 	blkdiscard "github.com/containerd/containerd/snapshots/devmapper/blkdiscard"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 	"golang.org/x/sys/unix"
 )
 

snapshots/devmapper/pool_device_test.go

@@ -24,7 +24,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"testing"
 	"time"
@@ -34,6 +33,7 @@ import (
 	"github.com/containerd/containerd/snapshots/devmapper/dmsetup"
 	"github.com/docker/go-units"
 	"github.com/sirupsen/logrus"
+	exec "golang.org/x/sys/execabs"
 	"gotest.tools/v3/assert"
 )
 

snapshots/devmapper/snapshotter.go

@@ -23,7 +23,6 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 	"sync"
@@ -37,6 +36,7 @@ import (
 	"github.com/hashicorp/go-multierror"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
+	exec "golang.org/x/sys/execabs"
 )
 
 const (

snapshots/overlay/overlayutils/check_test.go

@@ -22,11 +22,11 @@ package overlayutils
 import (
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"testing"
 
 	"github.com/containerd/containerd/pkg/testutil"
 	"github.com/containerd/continuity/testutil/loopback"
+	exec "golang.org/x/sys/execabs"
 )
 
 func testOverlaySupported(t testing.TB, expected bool, mkfs ...string) {

sys/oom_linux_test.go

@@ -20,11 +20,11 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"os/exec"
 	"testing"
 	"time"
 
 	"github.com/containerd/containerd/pkg/userns"
+	exec "golang.org/x/sys/execabs"
 	"gotest.tools/v3/assert"
 	is "gotest.tools/v3/assert/cmp"
 )

sys/reaper/reaper_unix.go

@@ -20,12 +20,12 @@
 package reaper
 
 import (
-	"os/exec"
 	"sync"
 	"time"
 
 	runc "github.com/containerd/go-runc"
 	"github.com/pkg/errors"
+	exec "golang.org/x/sys/execabs"
 	"golang.org/x/sys/unix"
 )
 

vendor/golang.org/x/sys/execabs/execabs.go

@@ -0,0 +1,102 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package execabs is a drop-in replacement for os/exec
+// that requires PATH lookups to find absolute paths.
+// That is, execabs.Command("cmd") runs the same PATH lookup
+// as exec.Command("cmd"), but if the result is a path
+// which is relative, the Run and Start methods will report
+// an error instead of running the executable.
+//
+// See https://blog.golang.org/path-security for more information
+// about when it may be necessary or appropriate to use this package.
+package execabs
+
+import (
+	"context"
+	"fmt"
+	"os/exec"
+	"path/filepath"
+	"reflect"
+	"unsafe"
+)
+
+// ErrNotFound is the error resulting if a path search failed to find an executable file.
+// It is an alias for exec.ErrNotFound.
+var ErrNotFound = exec.ErrNotFound
+
+// Cmd represents an external command being prepared or run.
+// It is an alias for exec.Cmd.
+type Cmd = exec.Cmd
+
+// Error is returned by LookPath when it fails to classify a file as an executable.
+// It is an alias for exec.Error.
+type Error = exec.Error
+
+// An ExitError reports an unsuccessful exit by a command.
+// It is an alias for exec.ExitError.
+type ExitError = exec.ExitError
+
+func relError(file, path string) error {
+	return fmt.Errorf("%s resolves to executable in current directory (.%c%s)", file, filepath.Separator, path)
+}
+
+// LookPath searches for an executable named file in the directories
+// named by the PATH environment variable. If file contains a slash,
+// it is tried directly and the PATH is not consulted. The result will be
+// an absolute path.
+//
+// LookPath differs from exec.LookPath in its handling of PATH lookups,
+// which are used for file names without slashes. If exec.LookPath's
+// PATH lookup would have returned an executable from the current directory,
+// LookPath instead returns an error.
+func LookPath(file string) (string, error) {
+	path, err := exec.LookPath(file)
+	if err != nil {
+		return "", err
+	}
+	if filepath.Base(file) == file && !filepath.IsAbs(path) {
+		return "", relError(file, path)
+	}
+	return path, nil
+}
+
+func fixCmd(name string, cmd *exec.Cmd) {
+	if filepath.Base(name) == name && !filepath.IsAbs(cmd.Path) {
+		// exec.Command was called with a bare binary name and
+		// exec.LookPath returned a path which is not absolute.
+		// Set cmd.lookPathErr and clear cmd.Path so that it
+		// cannot be run.
+		lookPathErr := (*error)(unsafe.Pointer(reflect.ValueOf(cmd).Elem().FieldByName("lookPathErr").Addr().Pointer()))
+		if *lookPathErr == nil {
+			*lookPathErr = relError(name, cmd.Path)
+		}
+		cmd.Path = ""
+	}
+}
+
+// CommandContext is like Command but includes a context.
+//
+// The provided context is used to kill the process (by calling os.Process.Kill)
+// if the context becomes done before the command completes on its own.
+func CommandContext(ctx context.Context, name string, arg ...string) *exec.Cmd {
+	cmd := exec.CommandContext(ctx, name, arg...)
+	fixCmd(name, cmd)
+	return cmd
+
+}
+
+// Command returns the Cmd struct to execute the named program with the given arguments.
+// See exec.Command for most details.
+//
+// Command differs from exec.Command in its handling of PATH lookups,
+// which are used when the program name contains no slashes.
+// If exec.Command would have returned an exec.Cmd configured to run an
+// executable from the current directory, Command instead
+// returns an exec.Cmd that will return an error from Start or Run.
+func Command(name string, arg ...string) *exec.Cmd {
+	cmd := exec.Command(name, arg...)
+	fixCmd(name, cmd)
+	return cmd
+}

vendor/modules.txt

@@ -444,6 +444,7 @@ golang.org/x/sync/errgroup
 golang.org/x/sync/semaphore
 # golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c
 ## explicit
+golang.org/x/sys/execabs
 golang.org/x/sys/internal/unsafeheader
 golang.org/x/sys/plan9
 golang.org/x/sys/unix