apparmor.d -> profiles

profiles/passwd

@@ -0,0 +1,50 @@
+# vim:syntax=apparmor
+# ------------------------------------------------------------------
+#
+#    Copyright (C) 2019-2021 Mikhail Morfikov
+#
+#    This program is free software; you can redistribute it and/or
+#    modify it under the terms of version 2 of the GNU General Public
+#    License published by the Free Software Foundation.
+#
+# ------------------------------------------------------------------
+
+abi <abi/3.0>,
+
+include <tunables/global>
+
+@{exec_path} = /{usr/,}bin/passwd
+profile passwd @{exec_path} {
+  include <abstractions/base>
+  include <abstractions/wutmp>
+  include <abstractions/authentication>
+  include <abstractions/nameservice-strict>
+
+  # To write records to the kernel auditing log.
+  capability audit_write,
+
+  # To set the right permission to the files in the /etc/.
+  # Since passwd reads and writes from /etc/ directory, the write permissions are requried by it.
+  # Note that, /etc/shadow is never written by passwd. passwd actually writes to /etc/nshadow and
+  # renames /etc/nshadow to /etc/shadow.
+  capability chown,
+  capability fsetid,
+
+  # passwd is a SETUID binary, but it looks like it doesn't want this CAP.
+  #capability setuid,
+
+  network netlink raw,
+
+  @{exec_path} mr,
+
+  owner @{PROC}/@{pid}/loginuid r,
+
+  /etc/shadow rw,
+  /etc/nshadow rw,
+
+  # A process first uses lckpwdf() to lock the lock file, thereby gaining exclusive rights to
+  # modify the /etc/passwd or /etc/shadow password database.
+  /etc/.pwd.lock rwk,
+
+  include if exists <local/passwd>
+}