From: James Morris <jmorris@namei.org>
To: Matthew Garrett <mjg59@google.com>
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: Fri, 29 Mar 2019 06:23:30 +1100 (AEDT) [thread overview]
Message-ID: <alpine.LRH.2.21.1903290621350.1769@namei.org> (raw)
In-Reply-To: <CACdnJusbi1jB+G0wMcj43wNik9Fiv3QCc8v30ztrFWg5-P-0iQ@mail.gmail.com>
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?
>
> > Secure boot gives you some assurance of the static state of the system at
> > boot time, and lockdown is certainly useful (with or without secure boot),
> > but it's not a complete solution to runtime kernel integrity protection by
> > any stretch of the imagination. I'm concerned about it being perceived as
> > such.
>
> What do you think the functionality gaps are in terms of ensuring
> kernel integrity (other than kernel flaws that allow the restrictions
> to be bypassed)?
I don't know of any non-flaw gaps.
--
James Morris
<jmorris@namei.org>
next prev parent reply other threads:[~2019-03-28 19:24 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 [this message]
2019-03-28 20:08 ` Matthew Garrett
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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