From: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: dhowells@redhat.com, keyrings@vger.kernel.org,
matthew.garrett@nebula.com,
linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org,
linux-kernel@vger.kernel.org, gnomes@lxorguk.ukuu.org.uk
Subject: Re: [PATCH] Lock down drivers that can have io ports, io mem, irqs and dma changed
Date: Tue, 22 Nov 2016 07:12:33 +0100 [thread overview]
Message-ID: <20161122061233.GA4762@light.dominikbrodowski.net> (raw)
In-Reply-To: <26173.1479769852@warthog.procyon.org.uk>
On Mon, Nov 21, 2016 at 11:10:52PM +0000, David Howells wrote:
> One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> wrote:
>
> > You need to filter or lock down kernel module options because a lot of
> > modules let you set the I/O port or similar (eg mmio) which means you can
> > hack the entire machine with say the 8250 driver just by using it with an
> > mmio of the right location to patch the secure state to zero just by
> > getting the ability to write to the modules conf file.
>
> Is the attached patch the right sort of idea? [Note that I haven't actually
> compiled most of these drivers to check my changes yet.]
>
> David
> ---
> commit 8613a9655dad98c3358d82a9c4310cebdcb852ae
> Author: David Howells <dhowells@redhat.com>
> Date: Mon Nov 21 22:43:27 2016 +0000
>
> Lock down drivers that can have io ports, io mem, irqs and dma changed
>
> Lock down drivers that can have io ports, io mem, irqs and dma channels
> changed so that they can't be used to cause hardware to access the kernel
> image.
>
> Notes:
>
> (1) module_isa_driver() gets an extra parameter that, if true, will cause
> the module load to be rejected if the kernel is locked down.
>
> (2) module_driver() calls module_lockdown_check() to ask if the module
> load should be rejected if the kernel is locked down. This is a macro
> that should be #undef'd and then redefined right before
> module_driver() is called.
>
> (3) module_pci_driver() is a wrapper around module_driver(), so the same
> macro is used as in (2).
>
> (4) A number of drivers use parport 'ports' - so I haven't touched those.
You might also need to disable CIS overrides and CIS firmware loading for PCMCIA
drivers, I presume. That needs two changes:
- Abort in drivers/pcmcia/ds.c::pcmcia_load_firmware() or disable
the CONFIG_PCMCIA_LOAD_CIS config option permanently.
- Abort in drivers/pcmcia/cistpl.c::pccard_store_cis() or remove
write access to the "cis" file in
drivers/pcmcia/cistpl.c::pccard_cis_attr
Best,
Dominik
next prev parent reply other threads:[~2016-11-22 6:12 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-16 21:47 [PATCH 00/16] Kernel lockdown David Howells
2016-11-16 21:47 ` [PATCH 01/16] Add the ability to lock down access to the running kernel image David Howells
[not found] ` <147933284407.19316.17886320817060158597.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-16 22:20 ` Borislav Petkov
2016-11-16 22:40 ` David Howells
2016-12-25 21:20 ` Pavel Machek
2016-12-25 21:44 ` David Howells
2016-11-16 21:47 ` [PATCH 02/16] efi: Get the secure boot status David Howells
2016-11-17 12:37 ` Lukas Wunner
2016-11-22 0:31 ` [PATCH 2/6] arm/efi: Allow invocation of arbitrary runtime services David Howells
2016-11-22 0:31 ` [PATCH 3/6] efi: Add SHIM and image security database GUID definitions David Howells
2016-11-22 0:32 ` [PATCH 4/6] efi: Get the secure boot status David Howells
2016-11-22 10:44 ` Lukas Wunner
[not found] ` <20161122104401.GC1552-JFq808J9C/izQB+pC5nmwQ@public.gmane.org>
2016-11-22 10:49 ` Ard Biesheuvel
2016-11-22 14:52 ` David Howells
[not found] ` <25371.1479826321-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-22 20:36 ` Lukas Wunner
2016-11-22 14:47 ` David Howells
2016-11-22 20:30 ` Lukas Wunner
2016-11-23 0:02 ` David Howells
[not found] ` <7199.1479826047-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-22 14:57 ` David Howells
2016-11-22 0:32 ` [PATCH 5/6] efi: Disable secure boot if shim is in insecure mode David Howells
2016-11-22 13:03 ` Lukas Wunner
2016-11-22 0:32 ` [PATCH 6/6] efi: Add EFI_SECURE_BOOT bit David Howells
2016-11-22 13:04 ` Lukas Wunner
2016-11-21 11:46 ` [PATCH 02/16] efi: Get the secure boot status David Howells
2016-11-21 19:58 ` Lukas Wunner
[not found] ` <20161117123731.GA11573-JFq808J9C/izQB+pC5nmwQ@public.gmane.org>
2016-11-21 11:42 ` David Howells
[not found] ` <29779.1479728545-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-21 11:52 ` Ard Biesheuvel
[not found] ` <CAKv+Gu-frVDhzORDRZ6XT+FxewsTgrxhXmM=DqaS6Ns4mJhQ9g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-21 12:41 ` David Howells
2016-11-21 13:14 ` Ard Biesheuvel
[not found] ` <CAKv+Gu8Lhm=u97hY1y+Y+Ladk=y7pSVNrow8ML1hQUJ9+74B-w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-21 15:17 ` Lukas Wunner
2016-11-21 15:25 ` Ard Biesheuvel
2016-11-22 0:31 ` [PATCH 1/6] x86/efi: Allow invocation of arbitrary runtime services David Howells
[not found] ` <147977469914.6360.17194649697208113702.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-22 10:20 ` Lukas Wunner
2016-11-22 14:17 ` David Howells
2016-11-22 14:58 ` Joe Perches
[not found] ` <1479826691.1942.11.camel-6d6DIl74uiNBDgjK7y7TUQ@public.gmane.org>
2016-11-22 15:52 ` David Howells
[not found] ` <24973.1479829961-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-22 16:25 ` Joe Perches
2016-11-22 16:40 ` David Howells
2016-11-22 16:51 ` Joe Perches
2016-11-16 21:47 ` [PATCH 03/16] efi: Disable secure boot if shim is in insecure mode David Howells
2016-11-16 21:47 ` [PATCH 04/16] efi: Lock down the kernel if booted in secure boot mode David Howells
2016-11-16 21:47 ` [PATCH 05/16] efi: Add EFI_SECURE_BOOT bit David Howells
2016-11-17 21:58 ` Ard Biesheuvel
2016-11-18 11:58 ` Josh Boyer
[not found] ` <CA+5PVA6F5qEnuL2UaXS9_fJ217J93cEZDDsz9Y2BPwHXcMdX-A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-18 12:10 ` Ard Biesheuvel
[not found] ` <CAKv+Gu_8r3oM-jvvuSiXTzxp0YMEVgc5KkScJ2UhGTaXm28L6w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-18 17:28 ` David Howells
2016-11-16 21:48 ` [PATCH 06/16] Add a sysrq option to exit secure boot mode David Howells
2016-11-16 21:48 ` [PATCH 07/16] kexec: Disable at runtime if the kernel is locked down David Howells
2016-11-16 21:48 ` [PATCH 08/16] Copy secure_boot flag in boot params across kexec reboot David Howells
2016-11-16 21:48 ` [PATCH 09/16] hibernate: Disable when the kernel is locked down David Howells
2016-11-16 21:48 ` [PATCH 10/16] PCI: Lock down BAR access " David Howells
[not found] ` <147933283664.19316.12454053022687659937.stgit-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-16 21:48 ` [PATCH 11/16] x86: Lock down IO port " David Howells
2016-11-16 21:49 ` [PATCH 16/16] x86: Restrict MSR " David Howells
2016-11-16 22:27 ` [PATCH 00/16] Kernel lockdown One Thousand Gnomes
2016-11-21 19:53 ` Ard Biesheuvel
2016-11-30 14:27 ` One Thousand Gnomes
2016-11-16 21:48 ` [PATCH 12/16] ACPI: Limit access to custom_method when the kernel is locked down David Howells
2016-11-16 21:48 ` [PATCH 13/16] asus-wmi: Restrict debugfs interface " David Howells
2016-11-16 21:48 ` [PATCH 14/16] Restrict /dev/mem and /dev/kmem " David Howells
2016-11-16 21:49 ` [PATCH 15/16] acpi: Ignore acpi_rsdp kernel param when the kernel has been " David Howells
2016-11-16 22:28 ` [PATCH 00/16] Kernel lockdown Justin Forbes
2016-11-21 23:10 ` [PATCH] Lock down drivers that can have io ports, io mem, irqs and dma changed David Howells
2016-11-22 6:12 ` Dominik Brodowski [this message]
2016-11-23 12:58 ` David Howells
2016-11-23 19:21 ` Dominik Brodowski
[not found] ` <20161123192143.GA482-SGhQLRGLuNwb6pqDj42GsMgv3T4z79SOrE5yTffgRl4@public.gmane.org>
2016-11-24 17:34 ` David Howells
2016-11-24 20:19 ` Dominik Brodowski
2016-11-25 14:49 ` David Howells
[not found] ` <26173.1479769852-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-28 22:32 ` Corey Minyard
2016-11-29 0:11 ` David Howells
2016-11-29 0:23 ` Corey Minyard
2016-11-29 14:03 ` David Howells
[not found] ` <6973.1480428211-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org>
2016-11-29 14:35 ` Corey Minyard
2016-11-30 14:41 ` One Thousand Gnomes
[not found] ` <20161130144105.2b6be4fe-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>
2016-11-30 16:25 ` David Howells
2016-11-29 10:40 ` David Howells
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