From: "Mickaël Salaün" <mic@digikod.net>
To: Andy Lutomirski <luto@amacapital.net>
Cc: LKML <linux-kernel@vger.kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Casey Schaufler <casey@schaufler-ca.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Daniel Mack <daniel@zonque.org>,
David Drysdale <drysdale@google.com>,
"David S . Miller" <davem@davemloft.net>,
Elena Reshetova <elena.reshetova@intel.com>,
James Morris <james.l.morris@oracle.com>,
Kees Cook <keescook@chromium.org>, Paul Moore <pmoore@redhat.com>,
Sargun Dhillon <sargun@sargun.me>,
"Serge E . Hallyn" <serge@hallyn.com>,
Will Drewry <wad@chromium.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
Linux API <linux-api@vger.kernel.org>,
LSM List <linux-security-module@vger.kernel.org>,
Network Development <netdev@vger.kernel.org>,
cgroups@vger.kernel.org
Subject: Re: [RFC v2 09/10] landlock: Handle cgroups
Date: Thu, 25 Aug 2016 16:44:13 +0200 [thread overview]
Message-ID: <57BF043D.4000300@digikod.net> (raw)
In-Reply-To: <CALCETrVqfTaY4gfwNdwynBqWwYh6xsGHaqdoA3uc_jHogbkA-A@mail.gmail.com>
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On 25/08/2016 13:09, Andy Lutomirski wrote:
> On Thu, Aug 25, 2016 at 3:32 AM, Mickaël Salaün <mic@digikod.net> wrote:
>> Add an eBPF function bpf_landlock_cmp_cgroup_beneath(opt, map, map_op)
>> to compare the current process cgroup with a cgroup handle, The handle
>> can match the current cgroup if it is the same or a child. This allows
>> to make conditional rules according to the current cgroup.
>>
>> A cgroup handle is a map entry created from a file descriptor referring
>> a cgroup directory (e.g. by opening /sys/fs/cgroup/X). In this case, the
>> map entry is of type BPF_MAP_HANDLE_TYPE_LANDLOCK_CGROUP_FD and the
>> inferred array map is of type BPF_MAP_ARRAY_TYPE_LANDLOCK_CGROUP.
>
> Can you elaborate on why this is useful? I.e. why not just supply
> different policies to different subtrees.
The main use case I see is to load the security policies at the start of
a user session for all processes but not enforce them right away. The
user can then keep a shell for Landlock administration tasks and lock
the other processes with a dedicated cgroup on the fly. This allows the
user to make unremovable Landlock security policies but only activate
them when needed for specific processes.
>
> Also, how does this interact with the current cgroup v1 vs v2 mess?
> As far as I can tell, no one can even really agree on what "what
> cgroup am I in" means right now.
I tested with cgroup-v2 but indeed, it seems a bit different with
cgroup-v1 :)
Does anyone know how to handle both cases?
>
>>
>> An unprivileged process can create and manipulate cgroups thanks to
>> cgroup delegation.
>
> What is cgroup delegation?
This is simply the action of changing the owner of cgroup sysfs files to
allow an unprivileged user to handle them (cf. Documentation/cgroup-v2.txt)
Mickaël
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next prev parent reply other threads:[~2016-08-25 14:47 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-25 10:32 [RFC v2 00/10] Landlock LSM: Unprivileged sandboxing Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 01/10] landlock: Add Kconfig Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 02/10] bpf: Move u64_to_ptr() to BPF headers and inline it Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 03/10] bpf,landlock: Add a new arraymap type to deal with (Landlock) handles Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 04/10] seccomp: Split put_seccomp_filter() with put_seccomp() Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 05/10] seccomp: Handle Landlock Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 06/10] landlock: Add LSM hooks Mickaël Salaün
2016-08-30 18:56 ` Andy Lutomirski
2016-08-30 20:10 ` Mickaël Salaün
2016-08-30 20:18 ` Andy Lutomirski
2016-08-30 20:27 ` Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 07/10] landlock: Add errno check Mickaël Salaün
2016-08-25 11:13 ` Andy Lutomirski
2016-08-25 10:32 ` [RFC v2 08/10] landlock: Handle file system comparisons Mickaël Salaün
2016-08-25 11:12 ` Andy Lutomirski
2016-08-25 14:10 ` Mickaël Salaün
2016-08-26 14:57 ` Andy Lutomirski
2016-08-27 13:45 ` Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 09/10] landlock: Handle cgroups Mickaël Salaün
2016-08-25 11:09 ` Andy Lutomirski
2016-08-25 14:44 ` Mickaël Salaün [this message]
2016-08-26 12:55 ` Tejun Heo
2016-08-26 14:20 ` Andy Lutomirski
2016-08-26 15:50 ` Tejun Heo
2016-08-26 2:14 ` Alexei Starovoitov
2016-08-26 15:10 ` Mickaël Salaün
2016-08-26 23:05 ` Alexei Starovoitov
2016-08-27 7:30 ` Andy Lutomirski
2016-08-27 18:11 ` Alexei Starovoitov
2016-08-28 8:14 ` Andy Lutomirski
2016-08-27 14:06 ` [RFC v2 09/10] landlock: Handle cgroups (performance) Mickaël Salaün
2016-08-27 18:06 ` Alexei Starovoitov
2016-08-27 19:35 ` Mickaël Salaün
2016-08-27 20:43 ` Alexei Starovoitov
2016-08-27 21:14 ` Mickaël Salaün
2016-08-28 8:13 ` Andy Lutomirski
2016-08-28 9:42 ` Mickaël Salaün
2016-08-30 18:55 ` Andy Lutomirski
2016-08-30 20:20 ` Mickaël Salaün
2016-08-30 20:23 ` Andy Lutomirski
2016-08-30 20:33 ` Mickaël Salaün
2016-08-30 20:55 ` Alexei Starovoitov
2016-08-30 21:45 ` Andy Lutomirski
2016-08-31 1:36 ` Alexei Starovoitov
2016-08-31 3:29 ` Andy Lutomirski
2016-08-27 14:19 ` [RFC v2 09/10] landlock: Handle cgroups (netfilter match) Mickaël Salaün
2016-08-27 18:32 ` Alexei Starovoitov
2016-08-27 14:34 ` [RFC v2 09/10] landlock: Handle cgroups (program types) Mickaël Salaün
2016-08-27 18:19 ` Alexei Starovoitov
2016-08-27 19:55 ` Mickaël Salaün
2016-08-27 20:56 ` Alexei Starovoitov
2016-08-27 21:18 ` Mickaël Salaün
2016-08-25 10:32 ` [RFC v2 10/10] samples/landlock: Add sandbox example Mickaël Salaün
2016-08-25 11:05 ` [RFC v2 00/10] Landlock LSM: Unprivileged sandboxing Andy Lutomirski
2016-08-25 13:57 ` Mickaël Salaün
2016-08-27 7:40 ` Andy Lutomirski
2016-08-27 15:10 ` Mickaël Salaün
2016-08-27 15:21 ` [RFC v2 00/10] Landlock LSM: Unprivileged sandboxing (cgroup delegation) Mickaël Salaün
2016-08-30 16:06 ` [RFC v2 00/10] Landlock LSM: Unprivileged sandboxing Andy Lutomirski
2016-08-30 19:51 ` Mickaël Salaün
2016-08-30 19:55 ` Andy Lutomirski
2016-09-15 9:19 ` Pavel Machek
2016-09-20 17:08 ` Mickaël Salaün
2016-09-24 7:45 ` Pavel Machek
2016-10-03 22:56 ` Kees Cook
2016-10-05 20:30 ` Mickaël Salaün
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