From: Matthew Garrett <matthewgarrett@google.com>
To: jmorris@namei.org
Cc: linux-security@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-api@vger.kernel.org,
Matthew Garrett <matthewgarrett@google.com>,
Matthew Garrett <mjg59@google.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
linux-efi@vger.kernel.org
Subject: [PATCH V33 30/30] efi: Restrict efivar_ssdt_load when the kernel is locked down
Date: Thu, 20 Jun 2019 18:19:41 -0700 [thread overview]
Message-ID: <20190621011941.186255-31-matthewgarrett@google.com> (raw)
In-Reply-To: <20190621011941.186255-1-matthewgarrett@google.com>
efivar_ssdt_load allows the kernel to import arbitrary ACPI code from an
EFI variable, which gives arbitrary code execution in ring 0. Prevent
that when the kernel is locked down.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-efi@vger.kernel.org
---
drivers/firmware/efi/efi.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 55b77c576c42..a9ea649e0512 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -31,6 +31,7 @@
#include <linux/acpi.h>
#include <linux/ucs2_string.h>
#include <linux/memblock.h>
+#include <linux/security.h>
#include <asm/early_ioremap.h>
@@ -242,6 +243,9 @@ static void generic_ops_unregister(void)
static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata;
static int __init efivar_ssdt_setup(char *str)
{
+ if (security_is_locked_down(LOCKDOWN_ACPI_TABLES))
+ return -EPERM;
+
if (strlen(str) < sizeof(efivar_ssdt))
memcpy(efivar_ssdt, str, strlen(str));
else
--
2.22.0.410.gd8fdbe21b5-goog
prev parent reply other threads:[~2019-06-21 1:19 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-21 1:19 [PATCH V33 00/30] Lockdown as an LSM Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 01/30] security: Support early LSMs Matthew Garrett
2019-06-21 3:21 ` Kees Cook
2019-06-21 19:26 ` Matthew Garrett
2019-06-21 5:23 ` Andy Lutomirski
2019-06-21 19:27 ` Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 02/30] security: Add a "locked down" LSM hook Matthew Garrett
2019-06-21 3:23 ` Kees Cook
2019-06-21 19:29 ` Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 03/30] security: Add a static lockdown policy LSM Matthew Garrett
2019-06-21 3:44 ` Kees Cook
2019-06-21 19:37 ` Matthew Garrett
2019-06-21 21:04 ` Matthew Garrett
2019-06-21 22:31 ` Mimi Zohar
2019-06-21 1:19 ` [PATCH V33 04/30] Enforce module signatures if the kernel is locked down Matthew Garrett
2019-06-21 3:46 ` Kees Cook
2019-06-21 1:19 ` [PATCH V33 05/30] Restrict /dev/{mem,kmem,port} when " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 06/30] kexec_load: Disable at runtime if " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 07/30] Copy secure_boot flag in boot params across kexec reboot Matthew Garrett
[not found] ` <20190621011941.186255-1-matthewgarrett-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2019-06-21 1:19 ` [PATCH V33 08/30] kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 09/30] kexec_file: Restrict at runtime if the kernel is locked down Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 10/30] hibernate: Disable when " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 11/30] uswsusp: " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 12/30] PCI: Lock down BAR access " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 13/30] x86: Lock down IO port " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 14/30] x86/msr: Restrict MSR " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 15/30] ACPI: Limit access to custom_method " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 16/30] acpi: Ignore acpi_rsdp kernel param when the kernel has been " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 17/30] acpi: Disable ACPI table override if the kernel is " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 18/30] Prohibit PCMCIA CIS storage when " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 19/30] Lock down TIOCSSERIAL Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 20/30] Lock down module params that specify hardware parameters (eg. ioport) Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 21/30] x86/mmiotrace: Lock down the testmmiotrace module Matthew Garrett
2019-06-26 12:46 ` Steven Rostedt
2019-06-21 1:19 ` [PATCH V33 22/30] Lock down /proc/kcore Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 23/30] Lock down tracing and perf kprobes when in confidentiality mode Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 24/30] bpf: Restrict bpf when kernel lockdown is " Matthew Garrett
2019-06-21 5:22 ` Andy Lutomirski
2019-06-21 20:05 ` Matthew Garrett
2019-06-26 20:22 ` James Morris
2019-06-27 0:57 ` Andy Lutomirski
2019-06-27 14:35 ` Stephen Smalley
2019-06-27 18:06 ` James Morris
2019-06-27 20:16 ` Stephen Smalley
2019-06-27 23:16 ` Matthew Garrett
2019-06-27 23:23 ` Andy Lutomirski
2019-06-27 23:27 ` Andy Lutomirski
2019-06-28 18:47 ` Matthew Garrett
2019-06-29 23:47 ` Andy Lutomirski
2019-06-21 1:19 ` [PATCH V33 25/30] Lock down perf when " Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 26/30] kexec: Allow kexec_file() with appropriate IMA policy when locked down Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 27/30] lockdown: Print current->comm in restriction messages Matthew Garrett
2019-06-21 4:09 ` Kees Cook
2019-06-21 1:19 ` [PATCH V33 28/30] debugfs: Restrict debugfs when the kernel is locked down Matthew Garrett
2019-06-21 1:19 ` [PATCH V33 29/30] tracefs: Restrict tracefs " Matthew Garrett
2019-06-26 13:07 ` Steven Rostedt
2019-06-26 19:39 ` Matthew Garrett
2019-06-21 1:19 ` Matthew Garrett [this message]
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