From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman)
To: David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Linux Containers
<containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
Oleg Nesterov <oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Eric Paris <eparis-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>,
James Bottomley
<James.Bottomley-JuX6DAaQMKPCXq6kfMZ53/egYHeGw8Jk@public.gmane.org>,
LSM List
<linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
keyrings-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
simo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
Subject: Re: Keyrings, user namespaces and the user_struct
Date: Wed, 26 Oct 2016 13:10:20 -0500 [thread overview]
Message-ID: <87mvhrrng3.fsf@xmission.com> (raw)
In-Reply-To: <9610.1477493338-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org> (David Howells's message of "Wed, 26 Oct 2016 15:48:58 +0100")
David Howells <dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> writes:
> Jann Horn <jann-XZ1E9jl8jIdeoWH0uzbU5w@public.gmane.org> wrote:
>
>> find_keyring_by_name() checks that the UID of the keyring's owner is mapped into
>> the current user namespace. But that doesn't catch the scenario I described:
>> The keyring is created in an attacker-created namespace and looked up from the
>> init namespace, into which all kuids are mapped.
>
> Ah - gotcha.
Unless I am misreading something it actually gets worse. You don't even
need a user namespace. You can just call keyctl_join_session_keyring
and the named keyring of your choice will be created.
Plus there are various really weird things in their where the keyring
names of _tid, _pid, _ses, get reused over and over again.
So it looks like there are some significant things to fix.
Eric
next prev parent reply other threads:[~2016-10-26 18:10 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20161026143856.GL3334@pc.thejh.net>
[not found] ` <CALCETrU0PqNYmWx70pugkhj-kAD5DSzSi3swhK+v12WMYZYUZA@mail.gmail.com>
[not found] ` <17576.1477412418@warthog.procyon.org.uk>
[not found] ` <17576.1477412418-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-10-25 16:41 ` Keyrings, user namespaces and the user_struct Jann Horn
2016-10-25 16:49 ` James Bottomley
2016-10-25 16:53 ` David Howells
[not found] ` <1477414605.3079.40.camel@HansenPartnership.com>
[not found] ` <1477414605.3079.40.camel-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org>
2016-10-25 17:06 ` Jann Horn
2016-10-25 17:30 ` David Howells
[not found] ` <20161025170602.GB24481@laptop.thejh.net>
[not found] ` <20161025170602.GB24481-GiL72Q0nGm9Crx9znvW9yA@public.gmane.org>
2016-10-25 18:05 ` James Bottomley
[not found] ` <1477418708.3079.52.camel@HansenPartnership.com>
[not found] ` <1477418708.3079.52.camel-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org>
2016-10-25 18:17 ` Jann Horn
[not found] ` <20161025181735.GC24481-GiL72Q0nGm9Crx9znvW9yA@public.gmane.org>
2016-10-25 18:21 ` James Bottomley
2016-10-25 19:34 ` Andy Lutomirski
[not found] ` <20947.1477428095@warthog.procyon.org.uk>
[not found] ` <20947.1477428095-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-10-25 20:51 ` James Bottomley
2016-10-26 5:54 ` Eric W. Biederman
[not found] ` <87shrju031.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2016-10-26 6:48 ` Eric W. Biederman
[not found] ` <CALCETrU0PqNYmWx70pugkhj-kAD5DSzSi3swhK+v12WMYZYUZA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-10-25 20:41 ` David Howells
2016-10-26 14:34 ` David Howells
[not found] ` <9243.1477492490-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-10-26 14:38 ` Jann Horn
[not found] ` <20161026143856.GL3334-J1fxOzX/cBvk1uMJSBkQmQ@public.gmane.org>
2016-10-26 14:48 ` David Howells
[not found] ` <9610.1477493338-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-10-26 18:10 ` Eric W. Biederman [this message]
[not found] ` <87mvhrrng3.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2016-10-26 18:35 ` David Howells
[not found] ` <3677.1477506925-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-10-27 16:11 ` David Howells
2016-10-27 16:18 ` Eric W. Biederman
[not found] ` <18335.1477414412-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-10-25 16:56 ` James Bottomley
2016-10-26 7:18 ` José Bollo
[not found] ` <18846.1477416621@warthog.procyon.org.uk>
[not found] ` <18846.1477416621-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-10-25 18:13 ` James Bottomley
[not found] ` <1477419204.3079.60.camel-d9PhHud1JfjCXq6kfMZ53/egYHeGw8Jk@public.gmane.org>
2016-10-25 18:22 ` Jann Horn
[not found] ` <20161025182206.GD24481@laptop.thejh.net>
[not found] ` <20161025182206.GD24481-GiL72Q0nGm9Crx9znvW9yA@public.gmane.org>
2016-10-25 18:25 ` James Bottomley
2016-10-26 4:45 ` Eric W. Biederman
[not found] ` <87y41bvhui.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2016-10-26 7:37 ` David Howells
2016-10-26 4:38 ` Eric W. Biederman
2016-10-26 11:43 ` David Howells
2016-10-25 16:20 David Howells
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=87mvhrrng3.fsf@xmission.com \
--to=ebiederm-as9lmozglivwk0htik3j/w@public.gmane.org \
--cc=James.Bottomley-JuX6DAaQMKPCXq6kfMZ53/egYHeGw8Jk@public.gmane.org \
--cc=containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org \
--cc=dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
--cc=eparis-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
--cc=keyrings-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org \
--cc=oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
--cc=simo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox