From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Matthew Garrett <matthewgarrett@google.com>
Cc: jmorris@namei.org, linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
Linn Crosetto <lcrosetto@gmail.com>,
David Howells <dhowells@redhat.com>,
Matthew Garrett <mjg59@google.com>,
Kees Cook <keescook@chromium.org>,
linux-acpi@vger.kernel.org
Subject: Re: [PATCH V40 16/29] acpi: Disable ACPI table override if the kernel is locked down
Date: Wed, 21 Aug 2019 00:08:48 +0200 [thread overview]
Message-ID: <18886542.jEbjgeBmpC@kreacher> (raw)
In-Reply-To: <20190820001805.241928-17-matthewgarrett@google.com>
On Tuesday, August 20, 2019 2:17:52 AM CEST Matthew Garrett wrote:
> From: Linn Crosetto <lcrosetto@gmail.com>
>
> >From the kernel documentation (initrd_table_override.txt):
>
> If the ACPI_INITRD_TABLE_OVERRIDE compile option is true, it is possible
> to override nearly any ACPI table provided by the BIOS with an
> instrumented, modified one.
>
> When lockdown is enabled, the kernel should disallow any unauthenticated
> changes to kernel space. ACPI tables contain code invoked by the kernel,
> so do not allow ACPI tables to be overridden if the kernel is locked down.
>
> Signed-off-by: Linn Crosetto <lcrosetto@gmail.com>
> Signed-off-by: David Howells <dhowells@redhat.com>
> Signed-off-by: Matthew Garrett <mjg59@google.com>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> cc: linux-acpi@vger.kernel.org
> Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> drivers/acpi/tables.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
> index de974322a197..b7c29a11c0c1 100644
> --- a/drivers/acpi/tables.c
> +++ b/drivers/acpi/tables.c
> @@ -20,6 +20,7 @@
> #include <linux/memblock.h>
> #include <linux/earlycpio.h>
> #include <linux/initrd.h>
> +#include <linux/security.h>
> #include "internal.h"
>
> #ifdef CONFIG_ACPI_CUSTOM_DSDT
> @@ -577,6 +578,11 @@ void __init acpi_table_upgrade(void)
> if (table_nr == 0)
> return;
>
> + if (security_locked_down(LOCKDOWN_ACPI_TABLES)) {
> + pr_notice("kernel is locked down, ignoring table override\n");
> + return;
> + }
> +
> acpi_tables_addr =
> memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
> all_tables_size, PAGE_SIZE);
>
next prev parent reply other threads:[~2019-08-20 22:08 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-20 0:17 [PATCH V40 00/29] Add kernel lockdown functionality Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 01/29] security: Support early LSMs Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 02/29] security: Add a "locked down" LSM hook Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 03/29] security: Add a static lockdown policy LSM Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 04/29] lockdown: Enforce module signatures if the kernel is locked down Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 05/29] lockdown: Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 06/29] kexec_load: Disable at runtime if " Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 07/29] lockdown: Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 08/29] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-08-30 14:26 ` Philipp Rudo
2019-08-20 0:17 ` [PATCH V40 09/29] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 10/29] hibernate: Disable when " Matthew Garrett
2019-08-20 21:43 ` Rafael J. Wysocki
2019-08-25 9:51 ` Pavel Machek
2019-08-20 0:17 ` [PATCH V40 11/29] PCI: Lock down BAR access " Matthew Garrett
2019-08-20 19:45 ` Bjorn Helgaas
2019-08-20 21:04 ` Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 12/29] x86: Lock down IO port " Matthew Garrett
2022-01-05 6:25 ` Kai-Heng Feng
2022-01-05 6:48 ` Matthew Garrett
2022-01-05 6:57 ` Kai-Heng Feng
2022-01-05 7:20 ` Matthew Garrett
2022-01-05 10:05 ` Kai-Heng Feng
2022-01-05 10:14 ` Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 13/29] x86/msr: Restrict MSR " Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 14/29] ACPI: Limit access to custom_method " Matthew Garrett
2019-08-20 22:07 ` Rafael J. Wysocki
2019-08-20 0:17 ` [PATCH V40 15/29] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-08-20 22:08 ` Rafael J. Wysocki
2019-08-20 0:17 ` [PATCH V40 16/29] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-08-20 22:08 ` Rafael J. Wysocki [this message]
2019-08-20 0:17 ` [PATCH V40 17/29] lockdown: Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 18/29] lockdown: Lock down TIOCSSERIAL Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 19/29] lockdown: Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-08-20 16:39 ` Jessica Yu
2019-08-20 0:17 ` [PATCH V40 20/29] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 21/29] lockdown: Lock down /proc/kcore Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 22/29] lockdown: Lock down tracing and perf kprobes when in confidentiality mode Matthew Garrett
2019-08-20 0:17 ` [PATCH V40 23/29] bpf: Restrict bpf when kernel lockdown is " Matthew Garrett
2019-08-20 0:18 ` [PATCH V40 24/29] lockdown: Lock down perf when " Matthew Garrett
2019-08-20 0:18 ` [PATCH V40 25/29] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-08-20 0:18 ` [PATCH V40 26/29] debugfs: Restrict debugfs when the kernel is " Matthew Garrett
2019-08-20 0:18 ` [PATCH V40 27/29] tracefs: Restrict tracefs " Matthew Garrett
2019-08-20 0:18 ` [PATCH V40 28/29] efi: Restrict efivar_ssdt_load " Matthew Garrett
2019-08-20 0:18 ` [PATCH V40 29/29] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-08-20 6:45 ` [PATCH V40 00/29] Add kernel lockdown functionality James Morris
2019-08-30 16:28 ` [PATCH V40 03/29] security: Add a static lockdown policy LSM David Howells
2019-09-04 16:51 ` Matthew Garrett
2019-09-10 10:06 ` Matthew Garrett
2019-08-30 16:31 ` [PATCH V40 04/29] lockdown: Enforce module signatures if the kernel is locked down David Howells
2019-09-04 16:57 ` Matthew Garrett
2019-08-30 16:32 ` [PATCH V40 23/29] bpf: Restrict bpf when kernel lockdown is in confidentiality mode David Howells
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