UEFI Secure Boot provides a mechanism for ensuring that the firmware will only load signed bootloaders and kernels. Certain use cases may also require that all kernel modules also be signed. Add a configuration option that to lock down the kernel - which includes requiring validly signed modules - if the kernel is secure-booted. Signed-off-by: David Howells <dhowells@xxxxxxxxxx> Acked-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> cc: linux-efi@xxxxxxxxxxxxxxx --- arch/x86/kernel/setup.c | 6 ++++-- security/Kconfig | 14 ++++++++++++++ security/lock_down.c | 1 + 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 7c2162f9e769..4e38327efb2e 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -64,6 +64,7 @@ #include <linux/dma-mapping.h> #include <linux/ctype.h> #include <linux/uaccess.h> +#include <linux/security.h> #include <linux/percpu.h> #include <linux/crash_dump.h> @@ -1039,6 +1040,9 @@ void __init setup_arch(char **cmdline_p) if (efi_enabled(EFI_BOOT)) efi_init(); + efi_set_secure_boot(boot_params.secure_boot); + init_lockdown(); + dmi_scan_machine(); dmi_memdev_walk(); dmi_set_dump_stack_arch_desc(); @@ -1197,8 +1201,6 @@ void __init setup_arch(char **cmdline_p) /* Allocate bigger log buffer */ setup_log_buf(1); - efi_set_secure_boot(boot_params.secure_boot); - reserve_initrd(); acpi_table_upgrade(); diff --git a/security/Kconfig b/security/Kconfig index 1e997be94ba2..a4fa8b826039 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -222,6 +222,20 @@ config ALLOW_LOCKDOWN_LIFT_BY_SYSRQ Allow the lockdown on a kernel to be lifted, by pressing a SysRq key combination on a wired keyboard. +config LOCK_DOWN_IN_EFI_SECURE_BOOT + bool "Lock down the kernel in EFI Secure Boot mode" + default n + select LOCK_DOWN_KERNEL + depends on EFI + help + UEFI Secure Boot provides a mechanism for ensuring that the firmware + will only load signed bootloaders and kernels. Secure boot mode may + be determined from EFI variables provided by the system firmware if + not indicated by the boot parameters. + + Enabling this option turns on results in kernel lockdown being + triggered if EFI Secure Boot is set. + source security/selinux/Kconfig source security/smack/Kconfig diff --git a/security/lock_down.c b/security/lock_down.c index 2c6b00f0c229..527f7e51dc8d 100644 --- a/security/lock_down.c +++ b/security/lock_down.c @@ -12,6 +12,7 @@ #include <linux/security.h> #include <linux/export.h> #include <linux/sysrq.h> +#include <linux/efi.h> #include <asm/setup.h> #ifdef CONFIG_ALLOW_LOCKDOWN_LIFT_BY_SYSRQ -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
