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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>,
	linux-acpi@vger.kernel.org
Subject: [PATCH V34 16/29] acpi: Disable ACPI table override if the kernel is locked down
Date: Fri, 21 Jun 2019 17:03:45 -0700	[thread overview]
Message-ID: <20190622000358.19895-17-matthewgarrett@google.com> (raw)
In-Reply-To: <20190622000358.19895-1-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>
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 8fccbe49612a..41d9ccd0e075 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -34,6 +34,7 @@
 #include <linux/memblock.h>
 #include <linux/earlycpio.h>
 #include <linux/initrd.h>
+#include <linux/security.h>
 #include "internal.h"
 
 #ifdef CONFIG_ACPI_CUSTOM_DSDT
@@ -539,6 +540,11 @@ 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);
-- 
2.22.0.410.gd8fdbe21b5-goog


  parent reply	other threads:[~2019-06-22  0:06 UTC|newest]

Thread overview: 80+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-22  0:03 [PATCH V34 00/29] Lockdown as an LSM Matthew Garrett
2019-06-22  0:03 ` [PATCH V34 01/29] security: Support early LSMs Matthew Garrett
2019-06-22 23:36   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 02/29] security: Add a "locked down" LSM hook Matthew Garrett
2019-06-22 23:37   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 03/29] security: Add a static lockdown policy LSM Matthew Garrett
2019-06-22 23:37   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 04/29] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-06-22 23:48   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 05/29] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-06-22 23:52   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 06/29] kexec_load: Disable at runtime if " Matthew Garrett
2019-06-22 23:52   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 07/29] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
2019-06-22 23:53   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 08/29] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-06-24  2:01   ` Dave Young
2019-06-25  2:35     ` Dave Young
2019-06-22  0:03 ` [PATCH V34 09/29] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-06-22 23:54   ` Kees Cook
2019-06-27  4:59   ` James Morris
2019-06-27 15:28     ` Matthew Garrett
2019-06-27 18:14       ` James Morris
2019-06-27 23:17         ` Matthew Garrett
2019-06-22  0:03 ` [PATCH V34 10/29] hibernate: Disable when " Matthew Garrett
2019-06-22 17:52   ` Pavel Machek
2019-06-24 13:21     ` Jiri Kosina
2019-07-10 15:26       ` Joey Lee
2019-07-11  4:11       ` joeyli
2019-06-22 23:55   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 11/29] PCI: Lock down BAR access " Matthew Garrett
2019-06-22 23:55   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 12/29] x86: Lock down IO port " Matthew Garrett
2019-06-22 23:58   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 13/29] x86/msr: Restrict MSR " Matthew Garrett
2019-06-22  0:03 ` [PATCH V34 14/29] ACPI: Limit access to custom_method " Matthew Garrett
2019-06-22 23:59   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 15/29] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-06-22 23:59   ` Kees Cook
2019-06-22  0:03 ` Matthew Garrett [this message]
2019-06-23  0:00   ` [PATCH V34 16/29] acpi: Disable ACPI table override if the kernel is " Kees Cook
2019-06-22  0:03 ` [PATCH V34 17/29] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-06-23  0:00   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 18/29] Lock down TIOCSSERIAL Matthew Garrett
2019-06-23  0:01   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 19/29] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-06-23  0:04   ` Kees Cook
2019-06-27  1:49   ` Daniel Axtens
2019-06-27 15:30     ` Matthew Garrett
2019-06-22  0:03 ` [PATCH V34 20/29] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-06-23  0:04   ` Kees Cook
2019-06-23 11:08   ` Thomas Gleixner
2019-06-22  0:03 ` [PATCH V34 21/29] Lock down /proc/kcore Matthew Garrett
2019-06-23  0:05   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 22/29] Lock down tracing and perf kprobes when in confidentiality mode Matthew Garrett
2019-06-23  0:09   ` Kees Cook
2019-06-23  1:57   ` Masami Hiramatsu
2019-06-22  0:03 ` [PATCH V34 23/29] bpf: Restrict bpf when kernel lockdown is " Matthew Garrett
2019-06-23  0:09   ` Kees Cook
2019-06-24 15:15   ` Daniel Borkmann
2019-06-24 19:54     ` Matthew Garrett
2019-06-24 20:08       ` Andy Lutomirski
2019-06-24 20:15         ` Matthew Garrett
2019-06-24 20:59         ` Daniel Borkmann
2019-06-24 21:30           ` Matthew Garrett
2019-06-22  0:03 ` [PATCH V34 24/29] Lock down perf when " Matthew Garrett
2019-06-23  0:12   ` Kees Cook
2019-06-22  0:03 ` [PATCH V34 25/29] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-06-22  0:03 ` [PATCH V34 26/29] debugfs: Restrict debugfs when the kernel is " Matthew Garrett
2019-06-22  0:03 ` [PATCH V34 27/29] tracefs: Restrict tracefs " Matthew Garrett
2019-06-22  0:03 ` [PATCH V34 28/29] efi: Restrict efivar_ssdt_load " Matthew Garrett
2019-06-23  0:14   ` Kees Cook
2019-06-25 15:00   ` Ard Biesheuvel
2019-06-22  0:03 ` [PATCH V34 29/29] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-06-23  0:25   ` Kees Cook
2019-06-24 23:01 ` [PATCH V34 00/29] Lockdown as an LSM James Morris
2019-06-24 23:47   ` Casey Schaufler
2019-06-24 23:56   ` Matthew Garrett
2019-06-25  6:04     ` James Morris
2019-06-25  8:16   ` John Johansen

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