fix: uniqMcs use all cpu

Signed-off-by: ningmingxiao <[email protected]>

Author: ningmingxiao

go-selinux/label/label_linux.go

@@ -30,6 +30,9 @@ func InitLabels(options []string) (plabel string, mlabel string, retErr error) {
 	if !selinux.GetEnabled() {
 		return "", "", nil
 	}
+	if selinux.GetContainerLabelsSize() == int(selinux.CategoryRange*(selinux.CategoryRange-1)/2) {
+		return "", "", fmt.Errorf("SELinux label exhaustion: %d labels used", selinux.GetContainerLabelsSize())
+	}
 	processLabel, mountLabel := selinux.ContainerLabels()
 	if processLabel != "" {
 		defer func() {

go-selinux/label/label_linux_test.go

@@ -2,6 +2,7 @@ package label
 
 import (
 	"errors"
+	"fmt"
 	"os"
 	"testing"
 
@@ -53,6 +54,24 @@ func TestInit(t *testing.T) {
 	}
 }
 
+func TestSELinuxLabelExhaustion(t *testing.T) {
+	needSELinux(t)
+	selinux.CategoryRange = 5
+	var testNull []string
+	for i := 0; i < 20; i++ {
+		_, _, err := InitLabels(testNull)
+		if i == 19 {
+			if err == nil {
+				t.Fatal("err should not be nil")
+			} else {
+				if err.Error() != fmt.Sprintf("SELinux label exhaustion: %d labels used", selinux.GetContainerLabelsSize()) {
+					t.Fatalf("unexpected error %s", err.Error())
+				}
+			}
+		}
+	}
+}
+
 func TestRelabel(t *testing.T) {
 	needSELinux(t)
 

go-selinux/selinux_linux.go

@@ -85,6 +85,12 @@ var (
 	labels         map[string]string
 )
 
+func GetContainerLabelsSize() int {
+	state.Lock()
+	defer state.Unlock()
+	return len(state.mcsList)
+}
+
 func policyRoot() string {
 	policyRootOnce.Do(func() {
 		policyRootVal = filepath.Join(selinuxDir, readConfig(selinuxTypeTag))