From: Kees Cook <keescook@chromium.org>
To: Topi Miettinen <toiwoton@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
Andy Lutomirski <luto@kernel.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Jonathan Corbet <corbet@lwn.net>, Tejun Heo <tj@kernel.org>,
Li Zefan <lizefan@huawei.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Serge Hallyn <serge.hallyn@canonical.com>,
James Morris <james.l.morris@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Howells <dhowells@redhat.com>,
David Woodhouse <David.Woodhouse@intel.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Petr Mladek <pmladek@suse.com>,
"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
"open list:CONTROL GROUP (CGROUP)" <cgroups@vger.kernel.org>,
"open list:CAPABILITIES" <linux-security-module@vger.kernel.org>
Subject: Re: [PATCH] capabilities: add capability cgroup controller
Date: Thu, 23 Jun 2016 14:03:46 -0700 [thread overview]
Message-ID: <CAGXu5jJtJJRGchihX8wXOo0NumtdFMT3P4JM=GPeqPt811aM3w@mail.gmail.com> (raw)
In-Reply-To: <1466694434-1420-1-git-send-email-toiwoton@gmail.com>
On Thu, Jun 23, 2016 at 8:07 AM, Topi Miettinen <toiwoton@gmail.com> wrote:
> There are many basic ways to control processes, including capabilities,
> cgroups and resource limits. However, there are far fewer ways to find
> out useful values for the limits, except blind trial and error.
>
> Currently, there is no way to know which capabilities are actually used.
> Even the source code is only implicit, in-depth knowledge of each
> capability must be used when analyzing a program to judge which
> capabilities the program will exercise.
>
> Add a new cgroup controller for monitoring of capabilities
> in the cgroup.
>
> Test case demonstrating basic capability monitoring and how the
> capabilities are combined at next level (boot to rdshell):
>
> (initramfs) cd /sys/fs
> (initramfs) mount -t cgroup2 cgroup cgroup
> (initramfs) cd cgroup
> (initramfs) echo +capability > cgroup.subtree_control
> (initramfs) mkdir test; cd test
> (initramfs) echo +capability > cgroup.subtree_control
> (initramfs) ls
> capability.used cgroup.events cgroup.subtree_control
> cgroup.controllers cgroup.procs
> (initramfs) mkdir first second
> (initramfs) sh
>
> BusyBox v1.22.1 (Debian 1:1.22.0-19) built-in shell (ash)
> Enter 'help' for a list of built-in commands.
>
> (initramfs) cd first
> (initramfs) echo $$ >cgroup.procs
> (initramfs) cat capability.used
> 0000000000000000 # nothing so far
> (initramfs) mknod /dev/z_$$ c 1 2
> (initramfs) cat capability.used
> 0000000008000000 # CAP_MKNOD
> (initramfs) cat ../capability.used
> 0000000008000000 # also seen at next higher level
> (initramfs) exit
> (initramfs) sh
>
> BusyBox v1.22.1 (Debian 1:1.22.0-19) built-in shell (ash)
> Enter 'help' for a list of built-in commands.
>
> (initramfs) cd second
> (initramfs) echo $$ >cgroup.procs
> (initramfs) cat capability.used
> 0000000000000000 # nothing so far
> (initramfs) chown 1234 /dev/z_*
> (initramfs) cat capability.used
> 0000000000000001 # CAP_CHROOT
nitpick: this is CAP_CHOWN, not CAP_CHROOT
-Kees
--
Kees Cook
Chrome OS & Brillo Security
WARNING: multiple messages have this Message-ID (diff)
From: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
To: Topi Miettinen <toiwoton-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Cc: LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Andy Lutomirski <luto-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
"Serge E. Hallyn" <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>,
Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>,
Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
Serge Hallyn
<serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
James Morris
<james.l.morris-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
David Woodhouse
<David.Woodhouse-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
Ard Biesheuvel
<ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
"Paul E. McKenney"
<paulmck-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>,
Petr Mladek <pmladek-IBi9RG/b67k@public.gmane.org>,
"open list:DOCUMENTATION"
<linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"open list:CONTROL GROUP (CGROUP)"
<cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"open list:CAPABILITIES"
<linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH] capabilities: add capability cgroup controller
Date: Thu, 23 Jun 2016 14:03:46 -0700 [thread overview]
Message-ID: <CAGXu5jJtJJRGchihX8wXOo0NumtdFMT3P4JM=GPeqPt811aM3w@mail.gmail.com> (raw)
In-Reply-To: <1466694434-1420-1-git-send-email-toiwoton-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
On Thu, Jun 23, 2016 at 8:07 AM, Topi Miettinen <toiwoton-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> There are many basic ways to control processes, including capabilities,
> cgroups and resource limits. However, there are far fewer ways to find
> out useful values for the limits, except blind trial and error.
>
> Currently, there is no way to know which capabilities are actually used.
> Even the source code is only implicit, in-depth knowledge of each
> capability must be used when analyzing a program to judge which
> capabilities the program will exercise.
>
> Add a new cgroup controller for monitoring of capabilities
> in the cgroup.
>
> Test case demonstrating basic capability monitoring and how the
> capabilities are combined at next level (boot to rdshell):
>
> (initramfs) cd /sys/fs
> (initramfs) mount -t cgroup2 cgroup cgroup
> (initramfs) cd cgroup
> (initramfs) echo +capability > cgroup.subtree_control
> (initramfs) mkdir test; cd test
> (initramfs) echo +capability > cgroup.subtree_control
> (initramfs) ls
> capability.used cgroup.events cgroup.subtree_control
> cgroup.controllers cgroup.procs
> (initramfs) mkdir first second
> (initramfs) sh
>
> BusyBox v1.22.1 (Debian 1:1.22.0-19) built-in shell (ash)
> Enter 'help' for a list of built-in commands.
>
> (initramfs) cd first
> (initramfs) echo $$ >cgroup.procs
> (initramfs) cat capability.used
> 0000000000000000 # nothing so far
> (initramfs) mknod /dev/z_$$ c 1 2
> (initramfs) cat capability.used
> 0000000008000000 # CAP_MKNOD
> (initramfs) cat ../capability.used
> 0000000008000000 # also seen at next higher level
> (initramfs) exit
> (initramfs) sh
>
> BusyBox v1.22.1 (Debian 1:1.22.0-19) built-in shell (ash)
> Enter 'help' for a list of built-in commands.
>
> (initramfs) cd second
> (initramfs) echo $$ >cgroup.procs
> (initramfs) cat capability.used
> 0000000000000000 # nothing so far
> (initramfs) chown 1234 /dev/z_*
> (initramfs) cat capability.used
> 0000000000000001 # CAP_CHROOT
nitpick: this is CAP_CHOWN, not CAP_CHROOT
-Kees
--
Kees Cook
Chrome OS & Brillo Security
next prev parent reply other threads:[~2016-06-23 21:04 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-23 15:07 [PATCH] capabilities: add capability cgroup controller Topi Miettinen
2016-06-23 15:07 ` Topi Miettinen
2016-06-23 21:03 ` Kees Cook [this message]
2016-06-23 21:03 ` Kees Cook
2016-06-23 21:38 ` Tejun Heo
2016-06-24 0:22 ` Topi Miettinen
2016-06-24 15:48 ` Tejun Heo
2016-06-24 15:59 ` Serge E. Hallyn
2016-06-24 16:35 ` Tejun Heo
2016-06-24 16:35 ` Tejun Heo
2016-06-24 16:59 ` Serge E. Hallyn
2016-06-24 17:21 ` Eric W. Biederman
2016-06-24 17:21 ` Eric W. Biederman
2016-06-24 17:39 ` Serge E. Hallyn
2016-06-26 19:03 ` Topi Miettinen
2016-06-26 19:03 ` Topi Miettinen
2016-06-28 4:57 ` Eric W. Biederman
2016-06-28 4:57 ` Eric W. Biederman
2016-07-02 11:20 ` Topi Miettinen
2016-07-02 11:20 ` Topi Miettinen
2016-06-24 17:24 ` Tejun Heo
2016-06-26 19:14 ` Topi Miettinen
2016-06-26 22:26 ` Tejun Heo
2016-06-27 14:54 ` Serge E. Hallyn
2016-06-27 19:10 ` Topi Miettinen
2016-06-27 19:17 ` Tejun Heo
2016-06-27 19:49 ` Serge E. Hallyn
2016-06-27 19:49 ` Serge E. Hallyn
2016-07-03 15:08 ` Topi Miettinen
2016-07-03 15:08 ` Topi Miettinen
2016-07-03 16:13 ` [PATCH] capabilities: audit capability use kbuild test robot
2016-07-03 16:13 ` kbuild test robot
2016-07-07 9:16 ` [PATCH] capabilities: add capability cgroup controller Petr Mladek
2016-07-07 20:27 ` Topi Miettinen
2016-07-08 9:13 ` Petr Mladek
2016-07-09 16:38 ` Topi Miettinen
2016-07-10 9:04 ` Topi Miettinen
2016-07-10 9:04 ` Topi Miettinen
2016-06-23 23:46 ` Andrew Morton
2016-06-23 23:46 ` Andrew Morton
2016-06-24 1:14 ` Topi Miettinen
2016-06-24 1:14 ` Topi Miettinen
2016-06-24 4:15 ` Andy Lutomirski
2016-06-24 4:15 ` Andy Lutomirski
2016-06-25 18:00 ` Djalal Harouni
2016-06-25 18:00 ` Djalal Harouni
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