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| author |   Linn Crosetto <lcrosetto@gmail.com> | 2019-08-19 17:17:52 -0700 |
|---|---|---|
| committer |   James Morris <jmorris@namei.org> | 2019-08-19 21:54:16 -0700 |
| commit | 6ea0e815fc5e18597724169caa6e4d46dd8e693d (patch) | |
| tree | e128c849c6b2a565b79967ee3b1457015993cc2d | |
| parent | acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down (diff) | |
| download | linux-dev-6ea0e815fc5e18597724169caa6e4d46dd8e693d.tar.xz linux-dev-6ea0e815fc5e18597724169caa6e4d46dd8e693d.zip | |
acpi: Disable ACPI table override if the kernel is locked down
>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>
| -rw-r--r-- | drivers/acpi/tables.c | 6 |
1 files changed, 6 insertions, 0 deletions
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); |