From: Vivek Goyal <vgoyal@redhat.com>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>,
Greg Kroah-Hartman <greg@kroah.com>,
kexec@lists.infradead.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Eric Paris <eparis@parisplace.org>
Subject: Re: [PATCH 0/6] kexec: A new system call to allow in kernel loading
Date: Fri, 22 Nov 2013 11:08:37 -0500 [thread overview]
Message-ID: <20131122160837.GJ4046@redhat.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1311221701510.22082@pobox.suse.cz>
On Fri, Nov 22, 2013 at 05:04:04PM +0100, Jiri Kosina wrote:
> On Fri, 22 Nov 2013, Eric Paris wrote:
>
> > Consider a cloud provider who gives their customer a machine where
> > they, the cloud provider, is specifying the kernel and initrd. This
> > is a real thing that people do today. Root on the machine has ZERO
> > control over the kernel, bootloader, and initrd. Check it out,
> > qemu/kvm can do this. But, there is no way to disable kexec if the
> > distro configures it in (well, there is in RHEL at least).
>
> If that root can load LKMs, access /dev/mem, or whatever else, there is
> not really a point disabling kexec anyway, is the same thing can be
> implemented (although with more hassle, of course) through these channels
> as well.
I am assuming that in above scenario, kernel will run in locked down
mode (something what matthew implemented for secureboot). Where /dev/mem
write access will be disabled and only signed modules will be loaded.
Thanks
Vivek
_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
WARNING: multiple messages have this Message-ID (diff)
From: Vivek Goyal <vgoyal@redhat.com>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Eric Paris <eparis@parisplace.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
kexec@lists.infradead.org, "H. Peter Anvin" <hpa@zytor.com>,
Matthew Garrett <mjg59@srcf.ucam.org>,
Greg Kroah-Hartman <greg@kroah.com>
Subject: Re: [PATCH 0/6] kexec: A new system call to allow in kernel loading
Date: Fri, 22 Nov 2013 11:08:37 -0500 [thread overview]
Message-ID: <20131122160837.GJ4046@redhat.com> (raw)
In-Reply-To: <alpine.LNX.2.00.1311221701510.22082@pobox.suse.cz>
On Fri, Nov 22, 2013 at 05:04:04PM +0100, Jiri Kosina wrote:
> On Fri, 22 Nov 2013, Eric Paris wrote:
>
> > Consider a cloud provider who gives their customer a machine where
> > they, the cloud provider, is specifying the kernel and initrd. This
> > is a real thing that people do today. Root on the machine has ZERO
> > control over the kernel, bootloader, and initrd. Check it out,
> > qemu/kvm can do this. But, there is no way to disable kexec if the
> > distro configures it in (well, there is in RHEL at least).
>
> If that root can load LKMs, access /dev/mem, or whatever else, there is
> not really a point disabling kexec anyway, is the same thing can be
> implemented (although with more hassle, of course) through these channels
> as well.
I am assuming that in above scenario, kernel will run in locked down
mode (something what matthew implemented for secureboot). Where /dev/mem
write access will be disabled and only signed modules will be loaded.
Thanks
Vivek
next prev parent reply other threads:[~2013-11-22 16:09 UTC|newest]
Thread overview: 180+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-20 17:50 [PATCH 0/6] kexec: A new system call to allow in kernel loading Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 1/6] kexec: Export vmcoreinfo note size properly Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-21 18:59 ` Greg KH
2013-11-21 18:59 ` Greg KH
2013-11-21 19:08 ` Vivek Goyal
2013-11-21 19:08 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 2/6] kexec: Move segment verification code in a separate function Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 3/6] resource: Provide new functions to walk through resources Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 4/6] kexec: A new system call, kexec_file_load, for in kernel kexec Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-21 19:03 ` Greg KH
2013-11-21 19:03 ` Greg KH
2013-11-21 19:06 ` Matthew Garrett
2013-11-21 19:06 ` Matthew Garrett
2013-11-21 19:13 ` Vivek Goyal
2013-11-21 19:13 ` Vivek Goyal
2013-11-21 19:19 ` Matthew Garrett
2013-11-21 19:19 ` Matthew Garrett
2013-11-21 19:24 ` Vivek Goyal
2013-11-21 19:24 ` Vivek Goyal
2013-11-22 18:57 ` Vivek Goyal
2013-11-22 18:57 ` Vivek Goyal
2013-11-23 3:39 ` Eric W. Biederman
2013-11-23 3:39 ` Eric W. Biederman
2013-11-25 16:39 ` Vivek Goyal
2013-11-25 16:39 ` Vivek Goyal
2013-11-26 12:23 ` Eric W. Biederman
2013-11-26 12:23 ` Eric W. Biederman
2013-11-26 14:27 ` Vivek Goyal
2013-11-26 14:27 ` Vivek Goyal
2013-12-19 12:54 ` Torsten Duwe
2013-12-19 12:54 ` Torsten Duwe
2013-12-20 14:19 ` Vivek Goyal
2013-12-20 14:19 ` Vivek Goyal
2013-12-20 23:11 ` Eric W. Biederman
2013-12-20 23:11 ` Eric W. Biederman
2013-12-20 23:20 ` Kees Cook
2013-12-20 23:20 ` Kees Cook
2013-12-21 11:38 ` Torsten Duwe
2013-12-21 11:38 ` Torsten Duwe
2014-01-02 20:39 ` Vivek Goyal
2014-01-02 20:39 ` Vivek Goyal
2014-01-02 20:56 ` H. Peter Anvin
2014-01-02 20:56 ` H. Peter Anvin
2014-01-06 21:33 ` Josh Boyer
2014-01-06 21:33 ` Josh Boyer
2014-01-07 4:22 ` H. Peter Anvin
2014-01-07 4:22 ` H. Peter Anvin
2013-12-20 23:20 ` H. Peter Anvin
2013-12-20 23:20 ` H. Peter Anvin
2013-12-21 1:32 ` Eric W. Biederman
2013-12-21 1:32 ` Eric W. Biederman
2013-12-21 3:32 ` H. Peter Anvin
2013-12-21 3:32 ` H. Peter Anvin
2013-12-21 12:15 ` Torsten Duwe
2013-12-21 12:15 ` Torsten Duwe
2013-11-21 19:16 ` Vivek Goyal
2013-11-21 19:16 ` Vivek Goyal
2013-11-22 1:03 ` Kees Cook
2013-11-22 1:03 ` Kees Cook
2013-11-22 2:13 ` Vivek Goyal
2013-11-22 2:13 ` Vivek Goyal
2013-11-22 20:42 ` Jiri Kosina
2013-11-22 20:42 ` Jiri Kosina
2014-01-17 19:17 ` Vivek Goyal
2014-01-17 19:17 ` Vivek Goyal
2013-11-29 3:10 ` Baoquan He
2013-11-29 3:10 ` Baoquan He
2013-12-02 15:27 ` WANG Chao
2013-12-02 15:27 ` WANG Chao
2013-12-02 15:44 ` Vivek Goyal
2013-12-02 15:44 ` Vivek Goyal
2013-12-04 1:35 ` Baoquan He
2013-12-04 1:35 ` Baoquan He
2013-12-04 17:19 ` Vivek Goyal
2013-12-04 17:19 ` Vivek Goyal
2013-12-04 1:56 ` Baoquan He
2013-12-04 1:56 ` Baoquan He
2013-12-04 8:19 ` Baoquan He
2013-12-04 8:19 ` Baoquan He
2013-12-04 17:32 ` Vivek Goyal
2013-12-04 17:32 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 5/6] kexec-bzImage: Support for loading bzImage using 64bit entry Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-21 19:07 ` Greg KH
2013-11-21 19:07 ` Greg KH
2013-11-21 19:21 ` Vivek Goyal
2013-11-21 19:21 ` Vivek Goyal
2013-11-22 15:24 ` H. Peter Anvin
2013-11-22 15:24 ` H. Peter Anvin
2013-11-28 11:35 ` Baoquan He
2013-11-28 11:35 ` Baoquan He
2013-12-02 15:36 ` Vivek Goyal
2013-12-02 15:36 ` Vivek Goyal
2013-11-20 17:50 ` [PATCH 6/6] kexec: Support for Kexec on panic using new system call Vivek Goyal
2013-11-20 17:50 ` Vivek Goyal
2013-11-28 11:28 ` Baoquan He
2013-11-28 11:28 ` Baoquan He
2013-12-02 15:30 ` Vivek Goyal
2013-12-02 15:30 ` Vivek Goyal
2013-12-04 1:51 ` Baoquan He
2013-12-04 1:51 ` Baoquan He
2013-12-04 17:20 ` Vivek Goyal
2013-12-04 17:20 ` Vivek Goyal
2013-12-04 1:41 ` Baoquan He
2013-12-04 1:41 ` Baoquan He
2013-12-04 17:19 ` Vivek Goyal
2013-12-04 17:19 ` Vivek Goyal
2013-11-21 18:58 ` [PATCH 0/6] kexec: A new system call to allow in kernel loading Greg KH
2013-11-21 18:58 ` Greg KH
2013-11-21 19:07 ` Vivek Goyal
2013-11-21 19:07 ` Vivek Goyal
2013-11-21 19:46 ` Vivek Goyal
2013-11-21 19:46 ` Vivek Goyal
2013-11-21 19:06 ` Geert Uytterhoeven
2013-11-21 19:06 ` Geert Uytterhoeven
2013-11-21 19:14 ` Vivek Goyal
2013-11-21 19:14 ` Vivek Goyal
2013-11-21 23:07 ` Eric W. Biederman
2013-11-21 23:07 ` Eric W. Biederman
2013-11-22 1:28 ` H. Peter Anvin
2013-11-22 1:28 ` H. Peter Anvin
2013-11-22 2:35 ` Vivek Goyal
2013-11-22 2:35 ` Vivek Goyal
2013-11-22 2:40 ` H. Peter Anvin
2013-11-22 2:40 ` H. Peter Anvin
2013-11-22 1:55 ` Vivek Goyal
2013-11-22 1:55 ` Vivek Goyal
2013-11-22 9:09 ` Geert Uytterhoeven
2013-11-22 9:09 ` Geert Uytterhoeven
2013-11-22 13:30 ` Jiri Kosina
2013-11-22 13:30 ` Jiri Kosina
2013-11-22 13:46 ` Vivek Goyal
2013-11-22 13:46 ` Vivek Goyal
2013-11-22 13:50 ` Jiri Kosina
2013-11-22 13:50 ` Jiri Kosina
2013-11-22 15:33 ` Vivek Goyal
2013-11-22 15:33 ` Vivek Goyal
2013-11-22 17:45 ` Kees Cook
2013-11-22 17:45 ` Kees Cook
2013-11-22 13:43 ` Vivek Goyal
2013-11-22 13:43 ` Vivek Goyal
2013-11-22 15:25 ` Geert Uytterhoeven
2013-11-22 15:25 ` Geert Uytterhoeven
2013-11-22 15:33 ` Jiri Kosina
2013-11-22 15:33 ` Jiri Kosina
2013-11-22 15:57 ` Eric Paris
2013-11-22 15:57 ` Eric Paris
2013-11-22 16:04 ` Jiri Kosina
2013-11-22 16:04 ` Jiri Kosina
2013-11-22 16:08 ` Vivek Goyal [this message]
2013-11-22 16:08 ` Vivek Goyal
2013-11-22 13:34 ` Eric W. Biederman
2013-11-22 13:34 ` Eric W. Biederman
2013-11-22 14:19 ` Vivek Goyal
2013-11-22 14:19 ` Vivek Goyal
2013-11-22 19:48 ` Greg KH
2013-11-22 19:48 ` Greg KH
2013-11-23 3:23 ` Eric W. Biederman
2013-11-23 3:23 ` Eric W. Biederman
2013-12-04 19:34 ` Vivek Goyal
2013-12-04 19:34 ` Vivek Goyal
2013-12-05 4:10 ` Eric W. Biederman
2013-12-05 4:10 ` Eric W. Biederman
2013-11-25 10:04 ` Michael Holzheu
2013-11-25 10:04 ` Michael Holzheu
2013-11-25 15:36 ` Vivek Goyal
2013-11-25 15:36 ` Vivek Goyal
2013-11-25 16:15 ` Michael Holzheu
2013-11-25 16:15 ` Michael Holzheu
2013-11-22 0:55 ` HATAYAMA Daisuke
2013-11-22 0:55 ` HATAYAMA Daisuke
2013-11-22 2:03 ` Vivek Goyal
2013-11-22 2:03 ` Vivek Goyal
2013-12-03 13:23 ` Baoquan He
2013-12-03 13:23 ` Baoquan He
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