selinux.Chcon should check legal rather then just label.Relabel

Since label.Relabel ends up calling into selinux.chcon, we should do the check for invalid directories under chcon. This will allow the selinux.Chcon function to also be verified. Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
opencontainers · Sep 26, 2022 · db3eeba · db3eeba
1 parent 00d547f
commit db3eeba
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Showing 2 changed files with 45 additions and 46 deletions.
diff --git a/go-selinux/label/label_linux.go b/go-selinux/label/label_linux.go
@@ -3,8 +3,6 @@ package label
 import (
 	"errors"
 	"fmt"
-	"os"
-	"os/user"
 	"strings"
 
 	"github.com/opencontainers/selinux/go-selinux"
@@ -113,50 +111,6 @@ func Relabel(path string, fileLabel string, shared bool) error {
 		return nil
 	}
 
-	exclude_paths := map[string]bool{
-		"/":           true,
-		"/bin":        true,
-		"/boot":       true,
-		"/dev":        true,
-		"/etc":        true,
-		"/etc/passwd": true,
-		"/etc/pki":    true,
-		"/etc/shadow": true,
-		"/home":       true,
-		"/lib":        true,
-		"/lib64":      true,
-		"/media":      true,
-		"/opt":        true,
-		"/proc":       true,
-		"/root":       true,
-		"/run":        true,
-		"/sbin":       true,
-		"/srv":        true,
-		"/sys":        true,
-		"/tmp":        true,
-		"/usr":        true,
-		"/var":        true,
-		"/var/lib":    true,
-		"/var/log":    true,
-	}
-
-	if home := os.Getenv("HOME"); home != "" {
-		exclude_paths[home] = true
-	}
-
-	if sudoUser := os.Getenv("SUDO_USER"); sudoUser != "" {
-		if usr, err := user.Lookup(sudoUser); err == nil {
-			exclude_paths[usr.HomeDir] = true
-		}
-	}
-
-	if path != "/" {
-		path = strings.TrimSuffix(path, "/")
-	}
-	if exclude_paths[path] {
-		return fmt.Errorf("SELinux relabeling of %s is not allowed", path)
-	}
-
 	if shared {
 		c, err := selinux.NewContext(fileLabel)
 		if err != nil {

diff --git a/go-selinux/selinux_linux.go b/go-selinux/selinux_linux.go
@@ -11,6 +11,7 @@ import (
 	"io/ioutil"
 	"math/big"
 	"os"
+	"os/user"
 	"path"
 	"path/filepath"
 	"strconv"
@@ -1083,6 +1084,50 @@ func chcon(fpath string, label string, recurse bool) error {
 		return nil
 	}
 
+	exclude_paths := map[string]bool{
+		"/":           true,
+		"/bin":        true,
+		"/boot":       true,
+		"/dev":        true,
+		"/etc":        true,
+		"/etc/passwd": true,
+		"/etc/pki":    true,
+		"/etc/shadow": true,
+		"/home":       true,
+		"/lib":        true,
+		"/lib64":      true,
+		"/media":      true,
+		"/opt":        true,
+		"/proc":       true,
+		"/root":       true,
+		"/run":        true,
+		"/sbin":       true,
+		"/srv":        true,
+		"/sys":        true,
+		"/tmp":        true,
+		"/usr":        true,
+		"/var":        true,
+		"/var/lib":    true,
+		"/var/log":    true,
+	}
+
+	if home := os.Getenv("HOME"); home != "" {
+		exclude_paths[home] = true
+	}
+
+	if sudoUser := os.Getenv("SUDO_USER"); sudoUser != "" {
+		if usr, err := user.Lookup(sudoUser); err == nil {
+			exclude_paths[usr.HomeDir] = true
+		}
+	}
+
+	if fpath != "/" {
+		fpath = strings.TrimSuffix(fpath, "/")
+	}
+	if exclude_paths[fpath] {
+		return fmt.Errorf("SELinux relabeling of %s is not allowed", fpath)
+	}
+
 	if !recurse {
 		return setFileLabel(fpath, label)
 	}