From f7db490354bc1fc92a439d3a25991b3117562770 Mon Sep 17 00:00:00 2001 From: Linn Crosetto Date: Tue, 30 Aug 2016 11:54:38 -0600 Subject: [PATCH] arm64: add kernel config option to lock down when in Secure Boot mode Add a kernel configuration option to lock down the kernel, to restrict userspace's ability to modify the running kernel when UEFI Secure Boot is enabled. Based on the x86 patch by Matthew Garrett. Determine the state of Secure Boot in the EFI stub and pass this to the kernel using the FDT. Signed-off-by: Linn Crosetto [bwh: Forward-ported to 4.10: adjust context] [Lukas Wunner: Forward-ported to 4.11: drop parts applied upstream] [bwh: Forward-ported to 4.15 and lockdown patch set: - Pass result of efi_get_secureboot() in stub through to efi_set_secure_boot() in main kernel - Use lockdown API and naming] Gbp-Pq: Topic features/all/lockdown Gbp-Pq: Name arm64-add-kernel-config-option-to-lock-down-when.patch --- drivers/firmware/efi/arm-init.c | 4 ++++ drivers/firmware/efi/efi.c | 3 ++- drivers/firmware/efi/libstub/fdt.c | 7 +++++++ include/linux/efi.h | 1 + 4 files changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c index 80d1a885def..56ee44ebac3 100644 --- a/drivers/firmware/efi/arm-init.c +++ b/drivers/firmware/efi/arm-init.c @@ -21,6 +21,7 @@ #include #include #include +#include #include @@ -252,6 +253,9 @@ void __init efi_init(void) "Unexpected EFI_MEMORY_DESCRIPTOR version %ld", efi.memmap.desc_version); + efi_set_secure_boot(params.secure_boot); + init_lockdown(); + if (uefi_init() < 0) { efi_memmap_unmap(); return; diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 232f4915223..89f26b721c8 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -648,7 +648,8 @@ static __initdata struct params fdt_params[] = { UEFI_PARAM("MemMap Address", "linux,uefi-mmap-start", mmap), UEFI_PARAM("MemMap Size", "linux,uefi-mmap-size", mmap_size), UEFI_PARAM("MemMap Desc. Size", "linux,uefi-mmap-desc-size", desc_size), - UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver) + UEFI_PARAM("MemMap Desc. Version", "linux,uefi-mmap-desc-ver", desc_ver), + UEFI_PARAM("Secure Boot Enabled", "linux,uefi-secure-boot", secure_boot) }; static __initdata struct params xen_fdt_params[] = { diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c index 8830fa601e4..532b02fbc5d 100644 --- a/drivers/firmware/efi/libstub/fdt.c +++ b/drivers/firmware/efi/libstub/fdt.c @@ -158,6 +158,13 @@ static efi_status_t update_fdt(efi_system_table_t *sys_table, void *orig_fdt, return efi_status; } } + + fdt_val32 = cpu_to_fdt32(efi_get_secureboot(sys_table)); + status = fdt_setprop(fdt, node, "linux,uefi-secure-boot", + &fdt_val32, sizeof(fdt_val32)); + if (status) + goto fdt_set_fail; + return EFI_SUCCESS; fdt_set_fail: diff --git a/include/linux/efi.h b/include/linux/efi.h index 9004e663588..d55d970cfc3 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -786,6 +786,7 @@ struct efi_fdt_params { u32 mmap_size; u32 desc_size; u32 desc_ver; + u32 secure_boot; }; typedef struct { -- 2.30.2