From: Andy Lutomirski <luto@amacapital.net>
To: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>,
James Morris <jmorris@namei.org>,
David Howells <dhowells@redhat.com>,
Alan Cox <gnomes@lxorguk.ukuu.org.uk>,
Linus Torvalds <torvalds@linux-foundation.org>,
Matthew Garrett <mjg59@google.com>,
Greg KH <gregkh@linuxfoundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Justin Forbes <jforbes@redhat.com>,
linux-man <linux-man@vger.kernel.org>, joeyli <jlee@suse.com>,
linux-security-module <linux-security-module@vger.kernel.org>,
Linux API <linux-api@vger.kernel.org>
Subject: Re: [GIT PULL] Kernel lockdown for secure boot
Date: Mon, 2 Apr 2018 18:47:05 -0700 [thread overview]
Message-ID: <70C7A8C3-3DCC-4448-9FBD-534ADDE2D6E6@amacapital.net> (raw)
In-Reply-To: <CAGXu5j+UWQWDacMvvRCke3xUOb7uTkxn=WaHzG4kJTKWh-6tAA@mail.gmail.com>
> On Apr 2, 2018, at 5:59 PM, Kees Cook <keescook@chromium.org> wrote:
>
>> On Mon, Apr 2, 2018 at 5:37 PM, Andy Lutomirski <luto@kernel.org> wrote:
>>> On 03/30/2018 05:46 PM, James Morris wrote:
>>>
>>>> On Sat, 31 Mar 2018, David Howells wrote:
>>>>
>>>> Date: Thu, 26 Oct 2017 17:37:38 +0100
>>>>
>>>> Hi James,
>>>>
>>>> Can you pull this patchset into security/next please? It has been in
>>>> linux-next since the beginning of March.
>>>>
>>>> It adds kernel lockdown support for EFI secure boot.
>>>
>>>
>>> Applied to
>>> git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git
>>> next-lockdown and next-testing
>>>
>>> Are there any known coverage gaps now?
>>>
>>>
>>>
>>
>> This is an attempt at a review. I'm replying here because I can't find the
>> actual relevant patch emails.
>>
>> Cover letter:
>>
>>> Here's a set of patches to institute a "locked-down mode" in the
>>> kernel and to trigger that mode if the kernel is booted in secure-boot >
>>> mode or through the command line.
>>
>> I think this is seriously problematic in that it's not well defined. It
>> sounds like "locked-down mode" means "make me feel good about something".
>
> Naming of this feature has been multi-year bikeshedding, so if we
> could just leave the name, that'd be nice.
Fair enough. How about enum kernel_lockdown_level with three modes?
>
>
>> "Restrict /dev/{mem,kmem,port} when the kernel is locked down": this should
>> probably split into one restriction for read and one for write.
>
> I think splitting read and write is only useful if there is a use-case
> for only blocking one of them. I struggle to imagine allowing write
> and blocking read, so really it's the case of wanting to allow read
> and disallow write. Is there actually a use-case for this? In all the
> "locked down" cases I've seen, both are desired.
>
Let’s suppose for the sake of argument that UEFI really has a good reason to block writes. Blocking reads (kprobes, perf, etc) sounds extremely annoying, especially if running a stock distro, and I’d much rather not do it unless there’s a specific use case that needs it.
next prev parent reply other threads:[~2018-04-03 1:47 UTC|newest]
Thread overview: 126+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-30 23:29 [GIT PULL] Kernel lockdown for secure boot David Howells
2018-03-31 0:46 ` James Morris
2018-04-03 0:37 ` Andy Lutomirski
2018-04-03 0:59 ` Kees Cook
2018-04-03 1:47 ` Andy Lutomirski [this message]
2018-04-03 7:06 ` David Howells
2018-04-03 15:11 ` Andy Lutomirski
2018-04-03 15:41 ` Alexei Starovoitov
2018-04-03 16:26 ` Andy Lutomirski
2018-04-03 16:29 ` Matthew Garrett
2018-04-03 16:45 ` Andy Lutomirski
2018-04-03 18:45 ` Kees Cook
2018-04-03 19:01 ` Andy Lutomirski
2018-04-03 19:07 ` Kees Cook
2018-04-03 19:29 ` Matthew Garrett
2018-04-03 21:51 ` Andy Lutomirski
2018-04-04 18:42 ` Peter Jones
2018-04-04 20:01 ` Thomas Gleixner
2018-04-04 20:18 ` Matthew Garrett
2018-04-05 18:47 ` Andy Lutomirski
2018-04-06 4:42 ` Peter Dolding
2018-04-03 17:16 ` David Howells
2018-04-03 19:01 ` Andy Lutomirski
2018-04-03 19:49 ` David Howells
2018-04-03 21:58 ` Andy Lutomirski
2018-04-03 22:32 ` David Howells
2018-04-03 22:39 ` Andy Lutomirski
2018-04-03 22:46 ` Linus Torvalds
2018-04-03 22:51 ` Matthew Garrett
2018-04-03 22:53 ` Andy Lutomirski
2018-04-03 23:08 ` Justin Forbes
2018-04-03 23:09 ` Matthew Garrett
2018-04-03 23:08 ` Linus Torvalds
2018-04-03 23:10 ` Linus Torvalds
2018-04-03 23:17 ` Matthew Garrett
2018-04-03 23:26 ` Linus Torvalds
2018-04-03 23:39 ` Linus Torvalds
2018-04-03 23:47 ` Matthew Garrett
2018-04-04 0:02 ` Linus Torvalds
2018-04-04 0:04 ` Matthew Garrett
2018-04-04 0:08 ` Linus Torvalds
2018-04-04 0:12 ` Matthew Garrett
2018-04-05 14:58 ` Alan Cox
2018-04-04 0:22 ` David Howells
2018-04-05 17:59 ` Alan Cox
2018-04-05 18:03 ` Matthew Garrett
2018-04-03 23:45 ` Matthew Garrett
2018-04-03 23:55 ` Linus Torvalds
2018-04-03 23:59 ` Matthew Garrett
2018-04-04 0:06 ` Linus Torvalds
2018-04-04 0:10 ` Matthew Garrett
2018-04-04 0:15 ` Linus Torvalds
2018-04-04 0:16 ` Matthew Garrett
2018-04-04 0:18 ` Andy Lutomirski
2018-04-04 0:19 ` Matthew Garrett
2018-04-04 9:04 ` Greg Kroah-Hartman
2018-04-04 0:25 ` Linus Torvalds
2018-04-04 0:33 ` Linus Torvalds
2018-04-04 0:46 ` Matthew Garrett
2018-04-04 0:56 ` Linus Torvalds
2018-04-04 1:13 ` Matthew Garrett
2018-04-04 1:43 ` Linus Torvalds
2018-04-04 4:30 ` Matthew Garrett
2018-04-04 12:57 ` Theodore Y. Ts'o
2018-04-04 13:02 ` Greg Kroah-Hartman
2018-04-04 13:34 ` Theodore Y. Ts'o
2018-04-04 13:57 ` Greg Kroah-Hartman
2018-04-04 13:29 ` Mike Galbraith
2018-04-04 16:20 ` Matthew Garrett
2018-04-08 22:00 ` Pavel Machek
2018-04-04 13:33 ` David Howells
2018-04-04 13:52 ` Theodore Y. Ts'o
2018-04-04 16:22 ` Matthew Garrett
2018-04-04 16:39 ` Andy Lutomirski
2018-04-04 16:42 ` Matthew Garrett
2018-04-04 16:46 ` Justin Forbes
2018-04-05 0:05 ` Peter Dolding
2018-04-05 0:20 ` Matthew Garrett
2018-04-04 13:57 ` David Howells
2018-04-04 16:09 ` Linus Torvalds
2018-04-04 16:17 ` Matthew Garrett
2018-04-04 6:56 ` Peter Dolding
2018-04-04 16:26 ` Matthew Garrett
2018-04-05 1:28 ` Peter Dolding
2018-04-04 1:30 ` Justin Forbes
2018-04-04 1:58 ` Linus Torvalds
2018-04-04 1:36 ` Justin Forbes
2018-04-04 0:17 ` Jann Horn
2018-04-04 0:23 ` Andy Lutomirski
2018-04-04 8:05 ` David Howells
2018-04-04 14:35 ` Andy Lutomirski
2018-04-04 14:44 ` David Howells
2018-04-04 15:43 ` Eric W. Biederman
2018-04-03 23:56 ` David Howells
2018-04-03 23:58 ` Linus Torvalds
2018-04-03 23:39 ` David Howells
2018-04-03 23:48 ` Andy Lutomirski
2018-04-08 8:23 ` Pavel Machek
2018-04-03 23:12 ` David Howells
2018-04-03 23:27 ` Linus Torvalds
2018-04-03 23:42 ` Andy Lutomirski
2018-04-03 20:53 ` Linus Torvalds
2018-04-03 20:54 ` Matthew Garrett
2018-04-03 21:01 ` Linus Torvalds
2018-04-03 21:08 ` Matthew Garrett
2018-04-03 21:21 ` Al Viro
2018-04-03 21:37 ` Matthew Garrett
2018-04-03 21:26 ` Linus Torvalds
2018-04-03 21:32 ` Matthew Garrett
2018-04-08 8:10 ` Pavel Machek
2018-03-31 10:20 ` David Howells
2018-04-03 13:25 ` Ard Biesheuvel
2018-04-03 21:48 ` James Morris
2018-04-05 17:53 ` Alan Cox
2018-11-21 12:05 ` [PATCH next-lockdown 0/1] debugfs EPERM fix for 'Kernel lockdown for secure boot' patch series Vasily Gorbik
2018-11-21 12:05 ` [PATCH next-lockdown 1/1] debugfs: avoid EPERM when no open file operation defined Vasily Gorbik
-- strict thread matches above, loose matches on Subject: below --
2018-04-04 2:34 [GIT PULL] Kernel lockdown for secure boot Alexei Starovoitov
2018-04-04 4:31 ` Matthew Garrett
2018-04-08 7:44 ` joeyli
2018-04-08 8:07 ` joeyli
2018-04-09 3:40 ` Alexei Starovoitov
2018-04-09 8:14 ` Daniel Borkmann
2018-04-09 13:55 ` joeyli
2017-10-26 16:37 David Howells
2017-10-26 18:22 ` Mimi Zohar
2017-10-26 19:20 ` James Morris
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