apparmor: fix replacement bug that adds new child to old parent

commit ec34fa24 upstream.

When set atomic replacement is used and the parent is updated before the
child, and the child did not exist in the old parent so there is no
direct replacement then the new child is incorrectly added to the old
parent. This results in the new parent not having the child(ren) that
it should and the old parent when being destroyed asserting the
following error.

AppArmor: policy_destroy: internal error, policy '<profile/name>' still
contains profiles
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

security/apparmor/policy.c

@@ -1193,7 +1193,7 @@ ssize_t aa_replace_profiles(void *udata, size_t size, bool noreplace)
 			/* aafs interface uses replacedby */
 			rcu_assign_pointer(ent->new->replacedby->profile,
 					   aa_get_profile(ent->new));
-			__list_add_profile(&parent->base.profiles, ent->new);
+			__list_add_profile(&newest->base.profiles, ent->new);
 			aa_put_profile(newest);
 		} else {
 			/* aafs interface uses replacedby */