From: Matthew Garrett <matthewgarrett@google.com>
To: jmorris@namei.org
Cc: linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
Linn Crosetto <linn@hpe.com>, David Howells <dhowells@redhat.com>,
Matthew Garrett <mjg59@google.com>,
Kees Cook <keescook@chromium.org>,
linux-acpi@vger.kernel.org
Subject: [PATCH V35 16/29] acpi: Disable ACPI table override if the kernel is locked down
Date: Mon, 15 Jul 2019 12:59:33 -0700 [thread overview]
Message-ID: <20190715195946.223443-17-matthewgarrett@google.com> (raw)
In-Reply-To: <20190715195946.223443-1-matthewgarrett@google.com>
From: Linn Crosetto <linn@hpe.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 <linn@hpe.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
---
drivers/acpi/tables.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c
index b32327759380..180ac4329763 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
@@ -578,6 +579,11 @@ 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);
--
2.22.0.510.g264f2c817a-goog
next prev parent reply other threads:[~2019-07-15 20:02 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-15 19:59 [PATCH V35 00/29] Kernel lockdown functionality Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 01/29] security: Support early LSMs Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 02/29] security: Add a "locked down" LSM hook Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 03/29] security: Add a static lockdown policy LSM Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 04/29] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 05/29] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 06/29] kexec_load: Disable at runtime if " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 07/29] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 08/29] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 09/29] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 10/29] hibernate: Disable when " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 11/29] PCI: Lock down BAR access " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 12/29] x86: Lock down IO port " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 13/29] x86/msr: Restrict MSR " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 14/29] ACPI: Limit access to custom_method " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 15/29] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-07-16 2:59 ` Dave Young
2019-07-16 20:34 ` Matthew Garrett
2019-07-15 19:59 ` Matthew Garrett [this message]
2019-07-15 19:59 ` [PATCH V35 17/29] Prohibit PCMCIA CIS storage when the kernel is " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 18/29] Lock down TIOCSSERIAL Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 19/29] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-07-15 23:26 ` James Morris
2019-07-15 19:59 ` [PATCH V35 20/29] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 21/29] Lock down /proc/kcore Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 22/29] Lock down tracing and perf kprobes when in confidentiality mode Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 23/29] bpf: Restrict bpf when kernel lockdown is " Matthew Garrett
2019-07-15 22:54 ` Daniel Borkmann
2019-07-16 20:32 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 24/29] Lock down perf when " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 25/29] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 26/29] debugfs: Restrict debugfs when the kernel is " Matthew Garrett
2019-07-15 23:17 ` James Morris
2019-07-15 19:59 ` [PATCH V35 27/29] tracefs: Restrict tracefs " Matthew Garrett
2019-07-16 23:14 ` Steven Rostedt
2019-07-16 23:22 ` Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 28/29] efi: Restrict efivar_ssdt_load " Matthew Garrett
2019-07-15 19:59 ` [PATCH V35 29/29] lockdown: Print current->comm in restriction messages Matthew Garrett
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