timedated: correctly set context on /etc/localtime

https://bugzilla.redhat.com/show_bug.cgi?id=1190377
(cherry picked from commit fad44453ec789f49529ea5244b2c2e4d5ad1d420)

src/shared/label.c

@@ -78,3 +78,21 @@ int symlink_label(const char *old_path, const char *new_path) {
 
         return mac_smack_fix(new_path, false, false);
 }
+
+int symlink_label_atomic(const char *old_path, const char *new_path) {
+        int r;
+
+        assert(old_path);
+        assert(new_path);
+
+        r = mac_selinux_create_file_prepare(new_path, S_IFLNK);
+        if (r < 0)
+                return r;
+
+        r = symlink_atomic(old_path, new_path);
+        mac_selinux_create_file_clear();
+        if (r < 0)
+                return r;
+
+        return mac_smack_fix(new_path, false, false);
+}

src/shared/label.h

@@ -28,3 +28,4 @@ int label_fix(const char *path, bool ignore_enoent, bool ignore_erofs);
 
 int mkdir_label(const char *path, mode_t mode);
 int symlink_label(const char *old_path, const char *new_path);
+int symlink_label_atomic(const char *old_path, const char *new_path);

src/timedate/timedated.c

@@ -34,6 +34,7 @@
 #include "clock-util.h"
 #include "conf-files.h"
 #include "path-util.h"
+#include "label.h"
 #include "fileio-label.h"
 #include "label.h"
 #include "bus-util.h"
@@ -123,7 +124,8 @@ static int context_write_data_timezone(Context *c) {
         if (!p)
                 return log_oom();
 
-        r = symlink_atomic(p, "/etc/localtime");
+        mac_selinux_init("/etc");
+        r = symlink_label_atomic(p, "/etc/localtime");
         if (r < 0)
                 return r;