vendor: opencontainers/selinux v1.5.2

full diff: https://github.com/opencontainers/selinux/compare/v1.5.1...v1.5.2

- Implement FormatMountLabel unconditionally
  Implementing FormatMountLabel on situations built without selinux
  should be possible; the context will be ignored if no SELinux is available.
- Remote potential race condition, where mcs label is freed
  Theorectially if you do not change the MCS Label then we free it and two
  commands later reserve it. If some other process was grabbing MCS Labels
  at the same time, the other process could get the same label.

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

vendor/github.com/opencontainers/selinux/go-selinux/label/label_selinux.go

@@ -3,7 +3,6 @@
 package label
 
 import (
-	"fmt"
 	"os"
 	"os/user"
 	"strings"
@@ -43,7 +42,7 @@ func InitLabels(options []string) (plabel string, mlabel string, Err error) {
 		if err != nil {
 			return "", "", err
 		}
-
+		mcsLevel := pcon["level"]
 		mcon, err := selinux.NewContext(mountLabel)
 		if err != nil {
 			return "", "", err
@@ -62,16 +61,21 @@ func InitLabels(options []string) (plabel string, mlabel string, Err error) {
 			}
 			if con[0] == "filetype" {
 				mcon["type"] = con[1]
+				continue
 			}
 			pcon[con[0]] = con[1]
 			if con[0] == "level" || con[0] == "user" {
 				mcon[con[0]] = con[1]
 			}
 		}
-		selinux.ReleaseLabel(processLabel)
-		processLabel = pcon.Get()
-		mountLabel = mcon.Get()
-		selinux.ReserveLabel(processLabel)
+		if pcon.Get() != processLabel {
+			if pcon["level"] != mcsLevel {
+				selinux.ReleaseLabel(processLabel)
+			}
+			processLabel = pcon.Get()
+			mountLabel = mcon.Get()
+			selinux.ReserveLabel(processLabel)
+		}
 	}
 	return processLabel, mountLabel, nil
 }
@@ -82,24 +86,6 @@ func GenLabels(options string) (string, string, error) {
 	return InitLabels(strings.Fields(options))
 }
 
-// FormatMountLabel returns a string to be used by the mount command.
-// The format of this string will be used to alter the labeling of the mountpoint.
-// The string returned is suitable to be used as the options field of the mount command.
-// If you need to have additional mount point options, you can pass them in as
-// the first parameter.  Second parameter is the label that you wish to apply
-// to all content in the mount point.
-func FormatMountLabel(src, mountLabel string) string {
-	if mountLabel != "" {
-		switch src {
-		case "":
-			src = fmt.Sprintf("context=%q", mountLabel)
-		default:
-			src = fmt.Sprintf("%s,context=%q", src, mountLabel)
-		}
-	}
-	return src
-}
-
 // SetFileLabel modifies the "path" label to the specified file label
 func SetFileLabel(path string, fileLabel string) error {
 	if !selinux.GetEnabled() || fileLabel == "" {