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From: Matthew Garrett <mjg59@google.com>
To: James Morris <jmorris@namei.org>
Cc: Andy Lutomirski <luto@kernel.org>,
	Stephen Hemminger <stephen@networkplumber.org>,
	Linux API <linux-api@vger.kernel.org>,
	LSM List <linux-security-module@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	David Howells <dhowells@redhat.com>,
	Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	Network Development <netdev@vger.kernel.org>,
	Chun-Yi Lee <jlee@suse.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Kees Cook <keescook@chromium.org>, Will Drewry <wad@chromium.org>
Subject: Re: [PATCH 23/27] bpf: Restrict kernel image access functions when the kernel is locked down
Date: Thu, 28 Mar 2019 13:08:39 -0700	[thread overview]
Message-ID: <CACdnJusN0XwKAFhCk-z2+u8Wn1OOzbSqQYYACFikcAtFqOA+WA@mail.gmail.com> (raw)
In-Reply-To: <alpine.LRH.2.21.1903290621350.1769@namei.org>

On Thu, Mar 28, 2019 at 12:23 PM James Morris <jmorris@namei.org> wrote:
>
> On Thu, 28 Mar 2019, Matthew Garrett wrote:
>
> > On Wed, Mar 27, 2019 at 8:15 PM James Morris <jmorris@namei.org> wrote:
> > > OTOH, this seems like a combination of mechanism and policy. The 3 modes
> > > are a help here, but I wonder if they may be too coarse grained still,
> > > e.g. if someone wants to allow a specific mechanism according to their own
> > > threat model and mitigations.
> >
> > In general the interfaces blocked by these patches could also be
> > blocked with an LSM, and I'd guess that people with more fine-grained
> > requirements would probably take that approach.
>
> So... I have to ask, why not use LSM for this in the first place?
>
> Either with an existing module or perhaps a lockdown LSM?

Some of it isn't really achievable that way - for instance, enforcing
module or kexec signatures. We have other mechanisms that can be used
to enable that which could be done at the more fine-grained level, but
a design goal was to make it possible to automatically enable a full
set of integrity protections under specified circumstances.

  reply	other threads:[~2019-03-28 20:08 UTC|newest]

Thread overview: 50+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-25 22:09 [PULL REQUEST] Lockdown patches for 5.2 Matthew Garrett
2019-03-25 22:09 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image Matthew Garrett
2019-03-26  5:30   ` Matthew Garrett
2019-03-25 22:09 ` [PATCH 02/27] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-03-25 22:09 ` [PATCH 03/27] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-03-25 22:09 ` [PATCH 04/27] kexec_load: Disable at runtime if " Matthew Garrett
2019-03-25 22:09 ` [PATCH 05/27] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-03-25 22:09 ` [PATCH 06/27] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-03-25 22:09 ` [PATCH 07/27] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-03-25 22:09 ` [PATCH 08/27] hibernate: Disable when " Matthew Garrett
2019-03-25 22:09 ` [PATCH 09/27] uswsusp: " Matthew Garrett
2019-03-25 22:09 ` [PATCH 10/27] PCI: Lock down BAR access " Matthew Garrett
2019-03-25 22:09 ` [PATCH 11/27] x86: Lock down IO port " Matthew Garrett
2019-03-25 22:09 ` [PATCH 12/27] x86/msr: Restrict MSR " Matthew Garrett
2019-03-25 23:40   ` Thomas Gleixner
2019-03-25 22:09 ` [PATCH 13/27] ACPI: Limit access to custom_method " Matthew Garrett
2019-03-25 22:09 ` [PATCH 14/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-03-25 22:09 ` [PATCH 15/27] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-03-25 22:09 ` [PATCH 16/27] acpi: Disable APEI error injection " Matthew Garrett
2019-03-25 22:09 ` [PATCH 17/27] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-03-25 22:09 ` [PATCH 18/27] Lock down TIOCSSERIAL Matthew Garrett
2019-03-25 22:09 ` [PATCH 19/27] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-03-25 22:09 ` [PATCH 20/27] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-03-25 23:35   ` Steven Rostedt
2019-03-25 22:09 ` [PATCH 21/27] Lock down /proc/kcore Matthew Garrett
2019-03-25 22:09 ` [PATCH 22/27] Lock down kprobes Matthew Garrett
2019-03-26 12:29   ` Masami Hiramatsu
2019-03-26 17:41     ` Matthew Garrett
2019-03-26 22:47       ` Masami Hiramatsu
2019-03-25 22:09 ` [PATCH 23/27] bpf: Restrict kernel image access functions when the kernel is locked down Matthew Garrett
2019-03-25 23:42   ` Stephen Hemminger
2019-03-25 23:59     ` Stephen Hemminger
2019-03-26  0:00     ` Daniel Borkmann
2019-03-26 13:54       ` Jordan Glover
2019-03-26  0:10     ` Andy Lutomirski
2019-03-26 18:57       ` James Morris
2019-03-26 19:22         ` Andy Lutomirski
2019-03-28  3:15           ` James Morris
2019-03-28 18:07             ` Matthew Garrett
2019-03-28 19:23               ` James Morris
2019-03-28 20:08                 ` Matthew Garrett [this message]
2019-03-26 20:19         ` Matthew Garrett
2019-03-25 22:09 ` [PATCH 24/27] Lock down perf Matthew Garrett
2019-03-25 22:09 ` [PATCH 25/27] debugfs: Restrict debugfs when the kernel is locked down Matthew Garrett
2019-03-26  0:31   ` Greg Kroah-Hartman
2019-03-26  0:38     ` Matthew Garrett
2019-03-26  0:43       ` Greg Kroah-Hartman
2019-03-25 22:09 ` [PATCH 26/27] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-03-25 22:09 ` [PATCH 27/27] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-03-26 15:33   ` Mimi Zohar

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