SELinux-Refpolicy Archive on
 help / color / Atom feed
From: Dominick Grift <>
To: Chris PeBenito <>
Cc: refpolicy <>
Subject: Re: [RFC] refining systemd mountpoints
Date: Thu, 9 Jan 2020 22:42:40 +0100
Message-ID: <20200109214240.GA2283901@brutus.lan> (raw)
In-Reply-To: <>

[-- Attachment #1: Type: text/plain, Size: 2456 bytes --]

On Thu, Jan 09, 2020 at 04:06:38PM -0500, Chris PeBenito wrote:
> I'd like to refine how the policy handles systemd's mounton so that it works
> similar to how we manage mountpoints for mount_t. Since systemd can be made
> to mount over just about anything, I'm looking at adding a new conditional
> that would allow init_t to mounton non_security_file_type, and then an
> interface like files_mountpoint().
> The question is for the implementation of the interface; I see two options,
> either the interface allows mounton for all file-like classes, or the
> classes are specified as a parameter:
> --------
> init.te:
> attribute init_mountpoint_type;
> allow init_t init_mountpoint_type:dir_file_class_set mounton;
> init.if:
> interface(`init_mountpoint',`
> typeattribute $1 init_mountpoint_type;
> ')
> --------
> or
> --------
> init.if:
> interface(`init_mountpoint',`
> allow init_t $1:$2 mounton;
> ')
> --------
> I like the first option because it is clearer since you can see the mounton
> in init.te, but that is excessive access.  The second option could be made
> to look like the first option, but it would need several attributes and
> interfaces, e.g. init_dir_mountpoint_type, init_file_mountpoint_type, etc.
> which isn't so desirable.
> Any thoughts on this?

I implemented the former in my policy. ie the dir_file_class_set equiv..

4163               (allow subj bind_path_obj_type_attribute (dirs (create)))
4164               (allow subj bind_path_obj_type_attribute list_dir_perms)
4165               (allow subj bind_path_obj_type_attribute (dir (mounton)))
4166               (allow subj bind_path_obj_type_attribute create_file_perms)
4167               (allow subj bind_path_obj_type_attribute (file (mounton)))

As you can see i even allow systemd to create the mountpoint in case it does not exist. For example if /etc/machine-id does not exist and I have a BindReadOnlyPath=/etc/machine-id then systemd will touch /etc/machine-id and mount it ro

It also generally buggy. Systemd does not (alway's) use setfscreatecon to create the mountpoints. And sometimes it does use setfscreatecon where it shouldnt.

> -- 
> Chris PeBenito

Key fingerprint = 5F4D 3CDB D3F8 3652 FBD8 02D5 3B6C 5F1D 2C7B 6B02
Dominick Grift

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 659 bytes --]

  reply index

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-09 21:06 Chris PeBenito
2020-01-09 21:42 ` Dominick Grift [this message]
2020-01-12 17:41   ` Nicolas Iooss
2020-01-13  9:42   ` Dominick Grift
2020-01-13 10:18     ` Dominick Grift

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200109214240.GA2283901@brutus.lan \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

SELinux-Refpolicy Archive on

Archives are clonable:
	git clone --mirror selinux-refpolicy/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 selinux-refpolicy selinux-refpolicy/ \
	public-inbox-index selinux-refpolicy

Example config snippet for mirrors

Newsgroup available over NNTP:

AGPL code for this site: git clone