All of lore.kernel.org
 help / color / mirror / Atom feed
From: Matthew Garrett <matthew.garrett@nebula.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>, Kees Cook <keescook@chromium.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "x86@kernel.org" <x86@kernel.org>,
	"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
	linux-security-module <linux-security-module@vger.kernel.org>
Subject: Re: [PATCH] x86: Lock down MSR writing in secure boot
Date: Wed, 13 Feb 2013 05:39:22 +0000	[thread overview]
Message-ID: <1360733962.18083.30.camel@x230.lan> (raw)
In-Reply-To: <511AE2CC.5040705@zytor.com>

On Tue, 2013-02-12 at 16:48 -0800, H. Peter Anvin wrote:

> OK... what none of this gets into:
> 
> Why should CAP_RAWIO be allowed on a secure boot system, when there are
> 2^n known ways of compromise a system with CAP_RAWIO?

CAP_SYS_RAWIO seems to have ended up being a catchall of "Maybe someone
who isn't entirely root should be able to do this", and not everything
it covers is equivalent to being able to compromise the running kernel.
I wouldn't argue with the idea that maybe we should just reappraise most
of the current uses of CAP_SYS_RAWIO, but removing capability checks
from places that currently have them seems like an invitation for
userspace breakage.

WARNING: multiple messages have this Message-ID (diff)
From: Matthew Garrett <matthew.garrett@nebula.com>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>, Kees Cook <keescook@chromium.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "x86@kernel.org" <x86@kernel.org>,
	"linux-efi@vger.kernel.org" <linux-efi@vger.kernel.org>,
	linux-security-module <linux-security-module@vger.kernel.org>
Subject: Re: [PATCH] x86: Lock down MSR writing in secure boot
Date: Wed, 13 Feb 2013 05:39:22 +0000	[thread overview]
Message-ID: <1360733962.18083.30.camel@x230.lan> (raw)
In-Reply-To: <511AE2CC.5040705@zytor.com>

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 832 bytes --]

On Tue, 2013-02-12 at 16:48 -0800, H. Peter Anvin wrote:

> OK... what none of this gets into:
> 
> Why should CAP_RAWIO be allowed on a secure boot system, when there are
> 2^n known ways of compromise a system with CAP_RAWIO?

CAP_SYS_RAWIO seems to have ended up being a catchall of "Maybe someone
who isn't entirely root should be able to do this", and not everything
it covers is equivalent to being able to compromise the running kernel.
I wouldn't argue with the idea that maybe we should just reappraise most
of the current uses of CAP_SYS_RAWIO, but removing capability checks
from places that currently have them seems like an invitation for
userspace breakage.
ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

  reply	other threads:[~2013-02-13  5:39 UTC|newest]

Thread overview: 84+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-08 19:12 [PATCH] x86: Lock down MSR writing in secure boot Kees Cook
2013-02-08 19:17 ` H. Peter Anvin
     [not found]   ` <00780235-deac-4f80-b936-867834e05661-2ueSQiBKiTY7tOexoI0I+QC/G2K4zDHf@public.gmane.org>
2013-02-08 19:18     ` Kees Cook
2013-02-08 19:18       ` Kees Cook
2013-02-08 19:42       ` H. Peter Anvin
2013-02-08 20:14         ` Kees Cook
     [not found]           ` <CAGXu5j+_mGzR+72YqORhErMUY1aF1H2urczZ8SwuJHZK-oZL6g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-02-08 20:18             ` H. Peter Anvin
2013-02-08 20:18               ` H. Peter Anvin
2013-02-08 20:28               ` Kees Cook
     [not found]                 ` <CAGXu5jLAufTRm=sDST0br_WEkn4o0Hpjv2jDP2Na=cCvuM+MGg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-02-08 20:34                   ` Matthew Garrett
2013-02-08 20:34                     ` Matthew Garrett
2013-02-08 21:02                     ` Kees Cook
2013-02-08 21:02                       ` Kees Cook
     [not found]                       ` <CAGXu5jKo2PfMBO4A0ZgQcrPuj8OHNaff+CjAesOAWkZc0vB9+Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-02-08 21:07                         ` Matthew Garrett
2013-02-08 21:07                           ` Matthew Garrett
     [not found]                           ` <1360357636.18083.19.camel-+5W/JHIUVxg@public.gmane.org>
2013-02-08 21:14                             ` Josh Boyer
2013-02-08 21:14                               ` Josh Boyer
2013-02-08 23:09                               ` Andy Lutomirski
2013-02-08 22:30                         ` H. Peter Anvin
2013-02-08 22:30                           ` H. Peter Anvin
2013-02-08 23:06                           ` Borislav Petkov
2013-02-08 23:26                             ` Matthew Garrett
2013-02-08 23:26                               ` Matthew Garrett
     [not found]                               ` <1360366012.18083.21.camel-+5W/JHIUVxg@public.gmane.org>
2013-02-09  1:22                                 ` H. Peter Anvin
2013-02-09  1:22                                   ` H. Peter Anvin
2013-02-09  1:29                                   ` Matthew Garrett
2013-02-09  1:29                                     ` Matthew Garrett
     [not found]                                     ` <1360373383.18083.23.camel-+5W/JHIUVxg@public.gmane.org>
2013-02-09  6:45                                       ` Kees Cook
2013-02-09  6:45                                         ` Kees Cook
     [not found]                                         ` <CAGXu5j+xvJ3L5ejxtZ-Jw3F6rV7OsrE0_HZCGu_er0rH2_PwKA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-02-09  9:29                                           ` Borislav Petkov
2013-02-09  9:29                                             ` Borislav Petkov
2013-02-09 15:10                                             ` Kees Cook
     [not found]                                             ` <20130209092925.GA17728-fF5Pk5pvG8Y@public.gmane.org>
2013-02-09 15:11                                               ` Matthew Garrett
2013-02-09 15:11                                                 ` Matthew Garrett
2013-02-13  0:48                                                 ` H. Peter Anvin
2013-02-13  5:39                                                   ` Matthew Garrett [this message]
2013-02-13  5:39                                                     ` Matthew Garrett
     [not found]                                                     ` <1360733962.18083.30.camel-+5W/JHIUVxg@public.gmane.org>
2013-02-13  6:12                                                       ` H. Peter Anvin
2013-02-13  6:12                                                         ` H. Peter Anvin
2013-02-13  6:27                                                         ` Matthew Garrett
2013-02-13  6:27                                                           ` Matthew Garrett
2013-02-13  6:33                                                           ` H. Peter Anvin
     [not found]                                                             ` <511B33BC.9080307-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2013-02-13  6:41                                                               ` Matthew Garrett
2013-02-13  6:41                                                                 ` Matthew Garrett
     [not found]                                                                 ` <1360737709.18083.36.camel-+5W/JHIUVxg@public.gmane.org>
2013-02-13 17:20                                                                   ` H. Peter Anvin
2013-02-13 17:20                                                                     ` H. Peter Anvin
2013-02-13 17:26                                                                     ` Matthew Garrett
2013-02-13 17:26                                                                       ` Matthew Garrett
2013-02-13 17:51                                                                       ` Casey Schaufler
2013-02-13 17:51                                                                         ` Casey Schaufler
     [not found]                                                                         ` <511BD291.1040003-iSGtlc1asvQWG2LlvL+J4A@public.gmane.org>
2013-02-13 17:56                                                                           ` Matthew Garrett
2013-02-13 17:56                                                                             ` Matthew Garrett
2013-02-13 18:44                                                                             ` H. Peter Anvin
2013-02-13 18:44                                                                               ` H. Peter Anvin
2013-02-13 18:51                                                                               ` Matthew Garrett
2013-02-13 18:51                                                                                 ` Matthew Garrett
2013-02-13 22:26                                                                         ` H. Peter Anvin
2013-02-13 22:26                                                                           ` H. Peter Anvin
2013-02-13 22:58                                                                           ` Casey Schaufler
2013-02-13 22:58                                                                             ` Casey Schaufler
     [not found]                                                                             ` <511C1A94.8020804-iSGtlc1asvQWG2LlvL+J4A@public.gmane.org>
2013-02-14  0:25                                                                               ` H. Peter Anvin
2013-02-14  0:25                                                                                 ` H. Peter Anvin
2013-02-14  0:44                                                                                 ` Casey Schaufler
2013-02-14  0:44                                                                                   ` Casey Schaufler
     [not found]                                                                                   ` <511C3389.5090604-iSGtlc1asvQWG2LlvL+J4A@public.gmane.org>
2013-02-14  1:04                                                                                     ` Matthew Garrett
2013-02-14  1:04                                                                                       ` Matthew Garrett
     [not found]                                                                                       ` <1360803872.18083.46.camel-+5W/JHIUVxg@public.gmane.org>
2013-02-14  1:08                                                                                         ` H. Peter Anvin
2013-02-14  1:08                                                                                           ` H. Peter Anvin
     [not found]                                                                                           ` <511C3927.90603-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>
2013-02-14  2:46                                                                                             ` Matthew Garrett
2013-02-14  2:46                                                                                               ` Matthew Garrett
2013-02-14  1:34                                                                                       ` Casey Schaufler
2013-02-14  1:34                                                                                         ` Casey Schaufler
2013-02-13  8:27                                                             ` Paolo Bonzini
2013-02-13 17:21                                                               ` H. Peter Anvin
     [not found]                                                               ` <511B4E61.1040604-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-02-13 17:22                                                                 ` H. Peter Anvin
2013-02-13 17:22                                                                   ` H. Peter Anvin
2013-02-13 19:55                                                                   ` Paolo Bonzini
     [not found]                                                                   ` <511B EFAD.1050206@redhat.com>
     [not found]                                                                     ` <511BEFAD.1050206-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2013-02-13 22:24                                                                       ` H. Peter Anvin
2013-02-13 22:24                                                                         ` H. Peter Anvin
2013-02-08 19:17 ` Matthew Garrett
2013-02-08 19:17   ` Matthew Garrett
2013-02-08 19:21   ` Kees Cook
     [not found]     ` <CAGXu5j+aXxQb_Jyn6G+JUdjNOF2EGo9pTw8dBYuZUTb+S1vWow-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2013-02-08 19:27       ` Matthew Garrett
2013-02-08 19:27         ` Matthew Garrett

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=1360733962.18083.30.camel@x230.lan \
    --to=matthew.garrett@nebula.com \
    --cc=bp@alien8.de \
    --cc=hpa@zytor.com \
    --cc=keescook@chromium.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.