From: "Serge E. Hallyn" <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>
To: Serge Hallyn <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org>
Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Oleg Nesterov <oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
"Eric W. Biederman"
<ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>,
Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Michael Kerrisk
<mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Subject: Re: [PATCH] Forbid invocation of kexec_load() outside initial PID namespace
Date: Mon, 6 Aug 2012 19:20:40 +0000 [thread overview]
Message-ID: <20120806192040.GA27023@mail.hallyn.com> (raw)
In-Reply-To: <1344122135.1422.2.camel@Nokia-N900-51-1>
Quoting Serge Hallyn (serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org):
> Eric,
>
> during the container reboot discussion, the agreement was reached that rebooting for real fron non-init pid ns is not safe. Restarting userspace (in pidns caller owns) is. I argue the same reasoning supports this.
>
> I haven't had a chance to review the patch, but the idea gets my ack. I'll look at the patch asap.
>
> I'm also fine with splitting cap_sys_boot into a user and system caps. The former would only be needed targeted to the userns of the init pid, while the latter would be required to init_user_ns. Then containers could safely be given cap_sys_restart or whatever, but not cap_sys_boot which authorizes kexec and machine reset/poweroff.
Splitting the cap up into CAP_RESTART (restart /sbin/init) and CAP_BOOT
(reboot hardware or kexec kernel) has the advantage that the capabilities
each remain simpler to parse, no 'in this context it means that'.
WARNING: multiple messages have this Message-ID (diff)
From: "Serge E. Hallyn" <serge@hallyn.com>
To: Serge Hallyn <serge@hallyn.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
"Daniel P. Berrange" <berrange@redhat.com>,
linux-kernel@vger.kernel.org,
containers@lists.linux-foundation.org,
Serge Hallyn <serge.hallyn@canonical.com>,
Daniel Lezcano <daniel.lezcano@free.fr>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Tejun Heo <tj@kernel.org>, Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH] Forbid invocation of kexec_load() outside initial PID namespace
Date: Mon, 6 Aug 2012 19:20:40 +0000 [thread overview]
Message-ID: <20120806192040.GA27023@mail.hallyn.com> (raw)
In-Reply-To: <1344122135.1422.2.camel@Nokia-N900-51-1>
Quoting Serge Hallyn (serge@hallyn.com):
> Eric,
>
> during the container reboot discussion, the agreement was reached that rebooting for real fron non-init pid ns is not safe. Restarting userspace (in pidns caller owns) is. I argue the same reasoning supports this.
>
> I haven't had a chance to review the patch, but the idea gets my ack. I'll look at the patch asap.
>
> I'm also fine with splitting cap_sys_boot into a user and system caps. The former would only be needed targeted to the userns of the init pid, while the latter would be required to init_user_ns. Then containers could safely be given cap_sys_restart or whatever, but not cap_sys_boot which authorizes kexec and machine reset/poweroff.
Splitting the cap up into CAP_RESTART (restart /sbin/init) and CAP_BOOT
(reboot hardware or kexec kernel) has the advantage that the capabilities
each remain simpler to parse, no 'in this context it means that'.
next prev parent reply other threads:[~2012-08-06 19:20 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-03 10:53 [PATCH] Forbid invocation of kexec_load() outside initial PID namespace Daniel P. Berrange
2012-08-03 10:53 ` Daniel P. Berrange
[not found] ` <1343991184-3619-1-git-send-email-berrange-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-08-03 11:25 ` richard -rw- weinberger
2012-08-03 11:25 ` richard -rw- weinberger
2012-08-03 12:45 ` Eric W. Biederman
2012-08-03 12:45 ` Eric W. Biederman
[not found] ` <cfa2e2c9-db52-40cd-979b-7a6084427190-2ueSQiBKiTY7tOexoI0I+QC/G2K4zDHf@public.gmane.org>
2012-08-03 12:52 ` Daniel P. Berrange
2012-08-03 12:52 ` Daniel P. Berrange
[not found] ` <20120803125210.GD12870-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2012-08-03 13:07 ` Eric W. Biederman
2012-08-03 13:07 ` Eric W. Biederman
2012-08-04 23:15 ` Serge Hallyn
2012-08-06 19:20 ` Serge E. Hallyn [this message]
2012-08-06 19:20 ` Serge E. Hallyn
[not found] ` <bef31b2b-429b-4b2b-981b-b230f9c6bfad-2ueSQiBKiTY7tOexoI0I+QC/G2K4zDHf@public.gmane.org>
2012-08-04 23:15 ` Serge Hallyn
2012-08-06 19:00 ` Serge E. Hallyn
2012-08-06 19:00 ` Serge E. Hallyn
[not found] ` <20120806190014.GA15267-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org>
2012-08-06 19:16 ` Eric W. Biederman
2012-08-06 19:16 ` Eric W. Biederman
[not found] ` <87r4rjn84y.fsf-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>
2012-08-06 19:24 ` Serge E. Hallyn
2012-08-06 19:24 ` Serge E. Hallyn
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