cmd/sync: execute chmod after chown to avoid setuid setgid failure (#…

…4418)

pkg/sync/sync.go

@@ -223,14 +223,15 @@ func copyPerms(dst object.ObjectStorage, obj object.Object, config *Config) {
 	start := time.Now()
 	key := obj.Key()
 	fi := obj.(object.File)
+	// chmod needs to be executed after chown, because chown will change setuid setgid to be invalid.
+	if err := dst.(object.FileSystem).Chown(key, fi.Owner(), fi.Group()); err != nil {
+		logger.Warnf("Chown %s to (%s,%s): %s", key, fi.Owner(), fi.Group(), err)
+	}
 	if !fi.IsSymlink() || !config.Links {
 		if err := dst.(object.FileSystem).Chmod(key, fi.Mode()); err != nil {
 			logger.Warnf("Chmod %s to %o: %s", key, fi.Mode(), err)
 		}
 	}
-	if err := dst.(object.FileSystem).Chown(key, fi.Owner(), fi.Group()); err != nil {
-		logger.Warnf("Chown %s to (%s,%s): %s", key, fi.Owner(), fi.Group(), err)
-	}
 	logger.Debugf("Copied permissions (%s:%s:%s) for %s in %s", fi.Owner(), fi.Group(), fi.Mode(), key, time.Since(start))
 }