Fix file mode

pkg/util/fs_util.go

@@ -216,16 +216,17 @@ func extractFile(dest string, hdr *tar.Header, tr io.Reader) error {
 		if err != nil {
 			return err
 		}
-		// manually set permissions on file, since the default umask (022) will interfere
-		if err = os.Chmod(path, mode); err != nil {
-			return err
-		}
 		if _, err = io.Copy(currFile, tr); err != nil {
 			return err
 		}
 		if err = currFile.Chown(uid, gid); err != nil {
 			return err
 		}
+		// manually set permissions on file, since the default umask (022) will interfere
+		// Must chmod after chown because chown resets the file mode.
+		if err = currFile.Chmod(mode); err != nil {
+			return err
+		}
 		currFile.Close()
 	case tar.TypeDir:
 		logrus.Debugf("creating dir %s", path)

pkg/util/fs_util_test.go

@@ -19,6 +19,7 @@ package util
 import (
 	"archive/tar"
 	"bytes"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -503,6 +504,16 @@ func TestExtractFile(t *testing.T) {
 				filesAreHardlinks("/bin/uncompress", "/bin/gzip"),
 			},
 		},
+		{
+			name:     "file with setuid bit",
+			contents: []byte("helloworld"),
+			hdrs:     []*tar.Header{fileHeader("./bar", "helloworld", 04644)},
+			checkers: []checker{
+				fileExists("/bar"),
+				fileMatches("/bar", []byte("helloworld")),
+				permissionsMatch("/bar", 0644|os.ModeSetuid),
+			},
+		},
 	}
 
 	for _, tc := range tcs {