From: Josh Boyer <jwboyer@xxxxxxxxxx> This option allows userspace to pass the RSDP address to the kernel, which makes it possible for a user to modify the workings of hardware . Reject the option when the kernel is locked down. Signed-off-by: Josh Boyer <jwboyer@xxxxxxxxxx> Signed-off-by: David Howells <dhowells@xxxxxxxxxx> Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> cc: Dave Young <dyoung@xxxxxxxxxx> cc: linux-acpi@xxxxxxxxxxxxxxx --- drivers/acpi/osl.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 9c0edf2fc0dd..06e7cffc4386 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -26,6 +26,7 @@ #include <linux/list.h> #include <linux/jiffies.h> #include <linux/semaphore.h> +#include <linux/security.h> #include <asm/io.h> #include <linux/uaccess.h> @@ -180,7 +181,7 @@ acpi_physical_address __init acpi_os_get_root_pointer(void) acpi_physical_address pa; #ifdef CONFIG_KEXEC - if (acpi_rsdp) + if (acpi_rsdp && !security_locked_down(LOCKDOWN_ACPI_TABLES)) return acpi_rsdp; #endif pa = acpi_arch_get_root_pointer(); -- 2.22.0.510.g264f2c817a-goog
