Linux-Fsdevel Archive on lore.kernel.org
 help / color / Atom feed
From: Paul Moore <paul@paul-moore.com>
To: Richard Guy Briggs <rgb@redhat.com>
Cc: containers@lists.linux-foundation.org, linux-api@vger.kernel.org,
	Linux-Audit Mailing List <linux-audit@redhat.com>,
	linux-fsdevel@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
	sgrubb@redhat.com, omosnace@redhat.com, dhowells@redhat.com,
	simo@redhat.com, Eric Paris <eparis@parisplace.org>,
	Serge Hallyn <serge@hallyn.com>,
	ebiederm@xmission.com, nhorman@tuxdriver.com,
	Dan Walsh <dwalsh@redhat.com>,
	mpatel@redhat.com
Subject: Re: [PATCH ghak90 V8 16/16] audit: add capcontid to set contid outside init_user_ns
Date: Wed, 5 Feb 2020 17:56:48 -0500
Message-ID: <CAHC9VhSsfBbfYmqLoR=QBgF5_VwbA8Dqqz97MjqwwJ6Jq6fHwA@mail.gmail.com> (raw)
In-Reply-To: <20200205003930.2efpm4tvrisgmj4t@madcap2.tricolour.ca>

On Tue, Feb 4, 2020 at 7:39 PM Richard Guy Briggs <rgb@redhat.com> wrote:
> On 2020-01-22 16:29, Paul Moore wrote:
> > On Tue, Dec 31, 2019 at 2:51 PM Richard Guy Briggs <rgb@redhat.com> wrote:
> > >
> > > Provide a mechanism similar to CAP_AUDIT_CONTROL to explicitly give a
> > > process in a non-init user namespace the capability to set audit
> > > container identifiers.
> > >
> > > Provide /proc/$PID/audit_capcontid interface to capcontid.
> > > Valid values are: 1==enabled, 0==disabled
> >
> > It would be good to be more explicit about "enabled" and "disabled" in
> > the commit description.  For example, which setting allows the target
> > task to set audit container IDs of it's children processes?
>
> Ok...
>
> > > Report this action in message type AUDIT_SET_CAPCONTID 1022 with fields
> > > opid= capcontid= old-capcontid=
> > >
> > > Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> > > ---
> > >  fs/proc/base.c             | 55 ++++++++++++++++++++++++++++++++++++++++++++++
> > >  include/linux/audit.h      | 14 ++++++++++++
> > >  include/uapi/linux/audit.h |  1 +
> > >  kernel/audit.c             | 35 +++++++++++++++++++++++++++++
> > >  4 files changed, 105 insertions(+)

...

> > > diff --git a/kernel/audit.c b/kernel/audit.c
> > > index 1287f0b63757..1c22dd084ae8 100644
> > > --- a/kernel/audit.c
> > > +++ b/kernel/audit.c
> > > @@ -2698,6 +2698,41 @@ static bool audit_contid_isowner(struct task_struct *tsk)
> > >         return false;
> > >  }
> > >
> > > +int audit_set_capcontid(struct task_struct *task, u32 enable)
> > > +{
> > > +       u32 oldcapcontid;
> > > +       int rc = 0;
> > > +       struct audit_buffer *ab;
> > > +
> > > +       if (!task->audit)
> > > +               return -ENOPROTOOPT;
> > > +       oldcapcontid = audit_get_capcontid(task);
> > > +       /* if task is not descendant, block */
> > > +       if (task == current)
> > > +               rc = -EBADSLT;
> > > +       else if (!task_is_descendant(current, task))
> > > +               rc = -EXDEV;
> >
> > See my previous comments about error code sanity.
>
> I'll go with EXDEV.
>
> > > +       else if (current_user_ns() == &init_user_ns) {
> > > +               if (!capable(CAP_AUDIT_CONTROL) && !audit_get_capcontid(current))
> > > +                       rc = -EPERM;
> >
> > I think we just want to use ns_capable() in the context of the current
> > userns to check CAP_AUDIT_CONTROL, yes?  Something like this ...
>
> I thought we had firmly established in previous discussion that
> CAP_AUDIT_CONTROL in anything other than init_user_ns was completely irrelevant
> and untrustable.

In the case of a container with multiple users, and multiple
applications, one being a nested orchestrator, it seems relevant to
allow that container to control which of it's processes are able to
exercise CAP_AUDIT_CONTROL.  Granted, we still want to control it
within the overall host, e.g. the container in question must be
allowed to run a nested orchestrator, but allowing the container
itself to provide it's own granularity seems like the right thing to
do.

> >   if (current_user_ns() != &init_user_ns) {
> >     if (!ns_capable(CAP_AUDIT_CONTROL) || !audit_get_capcontid())
> >       rc = -EPERM;
> >   } else if (!capable(CAP_AUDIT_CONTROL))
> >     rc = -EPERM;
> >

-- 
paul moore
www.paul-moore.com

  reply index

Thread overview: 95+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-31 19:48 [PATCH ghak90 V8 00/16] audit: implement container identifier Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 01/16] audit: collect audit task parameters Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 02/16] audit: add container id Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-01-30 17:53     ` Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 03/16] audit: read container ID of a process Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 04/16] audit: convert to contid list to check for orch/engine ownership Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-02-04 22:51     ` Richard Guy Briggs
2020-02-05 22:40       ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 05/16] audit: log drop of contid on exit of last task Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-02-04 23:02     ` Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 06/16] audit: log container info of syscalls Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 07/16] audit: add contid support for signalling the audit daemon Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-01-23 16:29     ` Richard Guy Briggs
2020-01-23 17:09       ` Paul Moore
2020-01-23 20:04         ` Richard Guy Briggs
2020-01-23 21:35           ` Paul Moore
2020-02-04 23:14             ` Richard Guy Briggs
2020-02-05 22:50               ` Paul Moore
2020-02-12 22:38                 ` Steve Grubb
2020-02-13  0:09                   ` Paul Moore
2020-02-13 21:44                     ` Paul Moore
2020-03-12 19:30                       ` Richard Guy Briggs
2020-03-13 16:29                         ` Paul Moore
2020-03-13 18:59                           ` Richard Guy Briggs
2020-03-18 20:56                             ` Paul Moore
2020-03-18 21:26                               ` Richard Guy Briggs
2020-03-18 21:42                                 ` Paul Moore
2020-03-18 21:55                                   ` Richard Guy Briggs
2020-03-18 22:06                                     ` Paul Moore
2020-03-19 22:02                                       ` Richard Guy Briggs
2020-03-24  0:16                                         ` Paul Moore
2020-03-24 21:01                                           ` Richard Guy Briggs
2020-03-29  3:11                                             ` Paul Moore
2020-03-30 13:47                                               ` Richard Guy Briggs
2020-03-30 14:26                                                 ` Paul Moore
2020-03-30 16:21                                                   ` Richard Guy Briggs
2020-03-30 17:34                                                     ` Paul Moore
2020-03-30 17:49                                                       ` Richard Guy Briggs
2020-03-30 19:55                                                         ` Paul Moore
2020-03-12 20:27                     ` Richard Guy Briggs
2020-03-13 16:42                       ` Paul Moore
2020-03-13 16:45                         ` Steve Grubb
2020-03-13 16:49                           ` Paul Moore
2020-03-13 19:23                         ` Richard Guy Briggs
2020-03-18 21:01                           ` Paul Moore
2020-03-18 21:41                             ` Richard Guy Briggs
2020-03-18 21:47                               ` Paul Moore
2020-03-19 21:47                                 ` Richard Guy Briggs
2020-03-20 21:56                                   ` Paul Moore
2020-03-25 12:29                                     ` Richard Guy Briggs
2020-03-29  3:17                                       ` Paul Moore
2020-03-30 15:23                                         ` Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 08/16] audit: add support for non-syscall auxiliary records Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 09/16] audit: add containerid support for user records Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 10/16] audit: add containerid filtering Richard Guy Briggs
2019-12-31 19:48 ` [PATCH ghak90 V8 11/16] audit: add support for containerid to network namespaces Richard Guy Briggs
2020-01-22 21:28   ` Paul Moore
2020-02-04 23:42     ` Richard Guy Briggs
2020-02-05 22:51       ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 12/16] audit: contid check descendancy and nesting Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2020-01-23 21:02     ` Richard Guy Briggs
2020-01-23 21:47       ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 13/16] audit: track container nesting Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2020-01-30 19:27     ` Richard Guy Briggs
2020-02-05 23:05       ` Paul Moore
2020-02-05 23:50         ` Richard Guy Briggs
2020-02-13 21:49           ` Paul Moore
2020-03-12 20:51             ` Richard Guy Briggs
2020-03-13 16:47               ` Paul Moore
2020-03-14 22:42                 ` Richard Guy Briggs
2020-03-17 18:28                   ` Richard Guy Briggs
2020-03-18 21:08                   ` Paul Moore
2020-01-31 14:50     ` Steve Grubb
2020-02-04 13:19       ` Richard Guy Briggs
2020-02-04 15:47         ` Steve Grubb
2020-02-04 15:52           ` Paul Moore
2020-02-04 18:12             ` Steve Grubb
2020-02-05 22:57               ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 14/16] audit: check contid depth and add limit config param Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 15/16] audit: check contid count per netns and add config param limit Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2019-12-31 19:48 ` [PATCH ghak90 V8 16/16] audit: add capcontid to set contid outside init_user_ns Richard Guy Briggs
2020-01-22 21:29   ` Paul Moore
2020-02-05  0:39     ` Richard Guy Briggs
2020-02-05 22:56       ` Paul Moore [this message]
2020-02-06 12:51         ` Richard Guy Briggs
2020-02-13 21:58           ` Paul Moore
2020-03-12 21:58             ` Richard Guy Briggs

Reply instructions:

You may reply publicly 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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to='CAHC9VhSsfBbfYmqLoR=QBgF5_VwbA8Dqqz97MjqwwJ6Jq6fHwA@mail.gmail.com' \
    --to=paul@paul-moore.com \
    --cc=containers@lists.linux-foundation.org \
    --cc=dhowells@redhat.com \
    --cc=dwalsh@redhat.com \
    --cc=ebiederm@xmission.com \
    --cc=eparis@parisplace.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-audit@redhat.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mpatel@redhat.com \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=nhorman@tuxdriver.com \
    --cc=omosnace@redhat.com \
    --cc=rgb@redhat.com \
    --cc=serge@hallyn.com \
    --cc=sgrubb@redhat.com \
    --cc=simo@redhat.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

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

Linux-Fsdevel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-fsdevel/0 linux-fsdevel/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 linux-fsdevel linux-fsdevel/ https://lore.kernel.org/linux-fsdevel \
		linux-fsdevel@vger.kernel.org
	public-inbox-index linux-fsdevel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-fsdevel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git