From: "AKASHI, Takahiro" <takahiro.akashi@linaro.org>
To: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>,
David Howells <dhowells@redhat.com>,
linux-security-module@vger.kernel.org,
gnomes@lxorguk.ukuu.org.uk, linux-efi <linux-efi@vger.kernel.org>,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
Matthew Garrett <mjg59@google.com>
Subject: Re: Firmware signing -- Re: [PATCH 00/27] security, efi: Add kernel lockdown
Date: Wed, 8 Nov 2017 15:15:54 +0900 [thread overview]
Message-ID: <20171108061551.GD7859@linaro.org> (raw)
In-Reply-To: <20171107230700.GJ22894@wotan.suse.de>
Luis,
Thank you for this heads-up.
On Wed, Nov 08, 2017 at 12:07:00AM +0100, Luis R. Rodriguez wrote:
> On Thu, Nov 02, 2017 at 06:10:41PM -0400, Mimi Zohar wrote:
> > On Thu, 2017-11-02 at 22:04 +0000, David Howells wrote:
> > > Mimi Zohar <zohar@linux.vnet.ibm.com> wrote:
> > >
> > > > > Only validly signed device firmware may be loaded.
> > > >
> > > > fw_get_filesystem_firmware() calls kernel_read_file_from_path() to
> > > > read the firmware, which calls into the security hooks. Is there
> > > > another place that validates the firmware signatures. I'm not seeing
> > > > which patch requires firmware to be signed?
> > >
> > > Luis has a set of patches for this. However, I'm not sure if that's going
> > > anywhere at the moment. Possibly I should remove this from the manpage for
> > > the moment.
>
> Remove it for now. The state of of affairs for firmware signing is complex given
> that we first wanted to address how to properly grow the API without making
> the API worse. This in and of itself was an effort, and that effort also
> evaluated two different development paradigms:
>
> o functional API
> o data driven API
>
> I only recently was convinced that functional API should be used, even for
> commonly used exported symbols,
Are you?
I haven't answered Linus' question, but my concern about functional APIs,
as far as firmware signing goes, is that we have no way to _enforce_
firmware signing to existing (i.e. verification-unaware) drivers if we need
an explicit call of a function, say, verify_firmware().
> and as such I've been going back and slowly
> grooming the firmware API with small atomic changes to first clean up the
> complex flag mess we have.
>
> Since I'm busy with that Takahiro AKASHI has taken up firmware singing effort
> but this will depend on the above small cleanup to be done first. I was busy
> with addressing existing bugs on the firmware API for a while, then company
> travel / conferences so was not able to address this, but I'm back now and
> I believe I should be able to tackle the cleanup now.
Good to hear.
> Only after this is merged can we expect a final respin of the firmware signing
> effort.
>
> > Or reflect that IMA-appraisal, if enabled, will enforce firmware being
> > validly signed.
>
> But FWICT lockdown is a built-in kernel thingy, unless lockdown implies IMA
> it would not be the place to refer to it.
I think that the situation is the same as in module signing.
-Takahiro AKASHI
> It seems the documentation was proposed to help users if an error was caught.
> That error should cover only what is being addressed in code on the kernel.
>
> Luis
next prev parent reply other threads:[~2017-11-08 6:12 UTC|newest]
Thread overview: 151+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-19 14:50 [PATCH 00/27] security, efi: Add kernel lockdown David Howells
2017-10-19 14:50 ` [PATCH 01/27] Add the ability to lock down access to the running kernel image David Howells
2017-10-20 23:19 ` James Morris
2017-10-19 14:50 ` [PATCH 02/27] Add a SysRq option to lift kernel lockdown David Howells
2017-10-19 17:20 ` Randy Dunlap
2017-10-19 22:12 ` David Howells
2017-11-07 17:39 ` Thiago Jung Bauermann
2017-11-07 22:56 ` David Howells
2017-10-19 14:50 ` [PATCH 03/27] Enforce module signatures if the kernel is locked down David Howells
2017-10-20 6:33 ` joeyli
2017-10-20 23:21 ` James Morris
2017-10-27 18:48 ` Mimi Zohar
2017-10-30 17:00 ` David Howells
2017-10-30 17:52 ` Mimi Zohar
2017-11-02 17:22 ` David Howells
2017-11-02 19:13 ` Mimi Zohar
2017-11-02 21:30 ` David Howells
2017-11-02 21:41 ` Mimi Zohar
2017-11-02 22:01 ` David Howells
2017-11-02 22:18 ` Mimi Zohar
2017-10-19 14:51 ` [PATCH 04/27] Restrict /dev/mem and /dev/kmem when " David Howells
2017-10-20 6:37 ` joeyli
2017-10-20 23:21 ` James Morris
2017-10-19 14:51 ` [PATCH 05/27] kexec: Disable at runtime if " David Howells
2017-10-20 6:38 ` joeyli
2017-10-20 23:22 ` James Morris
2017-10-19 14:51 ` [PATCH 06/27] Copy secure_boot flag in boot params across kexec reboot David Howells
2017-10-20 6:40 ` joeyli
2017-10-19 14:51 ` [PATCH 07/27] kexec_file: Disable at runtime if securelevel has been set David Howells
2017-10-20 23:26 ` James Morris
2017-10-23 15:54 ` Mimi Zohar
2017-10-26 7:42 ` joeyli
2017-10-26 14:17 ` Mimi Zohar
2017-10-27 19:30 ` Mimi Zohar
2017-10-27 19:32 ` Mimi Zohar
2017-10-28 8:34 ` joeyli
2017-10-29 22:26 ` Mimi Zohar
2017-10-30 9:00 ` David Howells
2017-10-30 12:01 ` Mimi Zohar
2017-10-26 15:02 ` David Howells
2017-10-26 15:46 ` Mimi Zohar
2017-10-30 15:49 ` David Howells
2017-10-30 16:43 ` Mimi Zohar
2017-11-02 17:00 ` David Howells
2017-10-26 14:51 ` David Howells
2017-11-02 17:29 ` David Howells
2017-10-19 14:51 ` [PATCH 08/27] hibernate: Disable when the kernel is locked down David Howells
2017-10-20 6:40 ` joeyli
2017-10-19 14:51 ` [PATCH 09/27] uswsusp: " David Howells
2017-10-20 6:41 ` joeyli
2017-10-20 23:29 ` James Morris
2017-10-19 14:51 ` [PATCH 10/27] PCI: Lock down BAR access " David Howells
2017-10-20 6:42 ` joeyli
2017-10-19 14:51 ` [PATCH 11/27] x86: Lock down IO port " David Howells
2017-10-20 6:43 ` joeyli
2017-10-19 14:52 ` [PATCH 12/27] x86/msr: Restrict MSR " David Howells
2017-10-20 6:43 ` joeyli
2017-10-20 18:09 ` Alan Cox
2017-10-20 20:48 ` David Howells
2017-10-21 4:39 ` joeyli
2017-10-23 14:49 ` David Howells
2017-10-25 14:03 ` joeyli
2017-10-19 14:52 ` [PATCH 13/27] asus-wmi: Restrict debugfs interface " David Howells
2017-10-20 6:44 ` joeyli
2017-10-19 14:52 ` [PATCH 14/27] ACPI: Limit access to custom_method " David Howells
2017-10-20 6:45 ` joeyli
2017-10-19 14:52 ` [PATCH 15/27] acpi: Ignore acpi_rsdp kernel param when the kernel has been " David Howells
2017-10-20 6:45 ` joeyli
2017-10-19 14:52 ` [PATCH 16/27] acpi: Disable ACPI table override if the kernel is " David Howells
2017-10-20 6:46 ` joeyli
2017-10-19 14:52 ` [PATCH 17/27] acpi: Disable APEI error injection " David Howells
2017-10-20 6:47 ` joeyli
2017-10-19 14:52 ` [PATCH 18/27] bpf: Restrict kernel image access functions when " David Howells
2017-10-19 22:18 ` Alexei Starovoitov
2017-10-20 2:47 ` joeyli
2017-10-20 8:08 ` David Howells
2017-10-20 15:57 ` jlee
2017-10-20 23:00 ` Alexei Starovoitov
2017-10-23 14:51 ` David Howells
2017-10-20 16:03 ` David Howells
2017-10-20 16:43 ` jlee
2017-10-23 14:53 ` David Howells
2017-10-25 7:07 ` joeyli
2017-10-19 22:48 ` David Howells
2017-10-19 23:31 ` Alexei Starovoitov
2017-11-09 17:15 ` David Howells
2017-10-19 14:52 ` [PATCH 19/27] scsi: Lock down the eata driver David Howells
2017-10-19 14:53 ` [PATCH 20/27] Prohibit PCMCIA CIS storage when the kernel is locked down David Howells
2017-10-19 14:53 ` [PATCH 21/27] Lock down TIOCSSERIAL David Howells
2017-10-19 14:53 ` [PATCH 22/27] Lock down module params that specify hardware parameters (eg. ioport) David Howells
2017-10-19 14:53 ` [PATCH 23/27] x86/mmiotrace: Lock down the testmmiotrace module David Howells
2017-10-19 14:53 ` [PATCH 24/27] debugfs: Disallow use of debugfs files when the kernel is locked down David Howells
2017-10-19 14:53 ` [PATCH 25/27] Lock down /proc/kcore David Howells
2017-10-21 2:11 ` James Morris
2017-10-23 14:56 ` David Howells
2017-10-19 14:53 ` [PATCH 26/27] efi: Add an EFI_SECURE_BOOT flag to indicate secure boot mode David Howells
2017-10-21 2:19 ` James Morris
2017-10-23 14:58 ` David Howells
2017-10-19 14:53 ` [PATCH 27/27] efi: Lock down the kernel if booted in " David Howells
2017-10-19 22:39 ` [PATCH 00/27] security, efi: Add kernel lockdown David Howells
2017-10-23 14:34 ` [PATCH 04/27] Restrict /dev/mem and /dev/kmem when the kernel is locked down David Howells
2017-10-24 10:48 ` Ethan Zhao
2017-10-24 14:56 ` David Howells
2017-11-02 22:01 ` [PATCH 00/27] security, efi: Add kernel lockdown Mimi Zohar
2017-11-02 22:04 ` Firmware signing -- " David Howells
2017-11-02 22:10 ` Mimi Zohar
2017-11-07 23:07 ` Luis R. Rodriguez
2017-11-08 6:15 ` AKASHI, Takahiro [this message]
2017-11-08 19:46 ` Luis R. Rodriguez
2017-11-09 1:48 ` AKASHI, Takahiro
2017-11-09 2:17 ` Mimi Zohar
2017-11-09 4:46 ` AKASHI, Takahiro
2017-11-10 13:37 ` Mimi Zohar
2017-11-11 2:32 ` Alan Cox
2017-11-13 11:49 ` Mimi Zohar
2017-11-13 17:42 ` Luis R. Rodriguez
2017-11-13 21:08 ` Alan Cox
2017-12-04 19:51 ` Luis R. Rodriguez
2017-12-07 15:32 ` Alan Cox
2017-11-13 21:44 ` David Howells
2017-11-13 22:09 ` Linus Torvalds
2017-11-14 0:20 ` Alan Cox
2017-11-14 12:21 ` Mimi Zohar
2017-11-14 12:38 ` Greg Kroah-Hartman
2017-11-14 13:17 ` Mimi Zohar
2017-11-14 17:34 ` Linus Torvalds
2017-11-14 19:58 ` Matthew Garrett
2017-11-14 20:18 ` Linus Torvalds
2017-11-14 20:31 ` Matthew Garrett
2017-11-14 20:35 ` Linus Torvalds
2017-11-14 20:37 ` Matthew Garrett
2017-11-14 20:50 ` Luis R. Rodriguez
2017-11-14 20:55 ` Matthew Garrett
2017-11-14 22:14 ` James Bottomley
2017-11-14 22:17 ` Matthew Garrett
2017-11-14 22:31 ` James Bottomley
2017-11-14 22:34 ` Matthew Garrett
2017-11-15 11:49 ` Mimi Zohar
2017-11-15 17:52 ` Luis R. Rodriguez
2017-11-15 19:56 ` Mimi Zohar
2017-11-15 20:46 ` Luis R. Rodriguez
2017-11-16 0:05 ` Mimi Zohar
2017-12-05 10:27 ` Pavel Machek
2017-12-07 23:02 ` Luis R. Rodriguez
2017-12-08 17:11 ` Alan Cox
2017-11-10 1:46 ` Luis R. Rodriguez
2017-11-10 13:45 ` Mimi Zohar
2017-11-13 18:50 ` Luis R. Rodriguez
2017-11-13 19:08 ` Luis R. Rodriguez
2017-11-08 20:01 ` Mimi Zohar
2017-11-08 20:09 ` Luis R. Rodriguez
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