From 78feacc44057916161365d079ae92aa0baa679f8 Mon Sep 17 00:00:00 2001 From: Patrick Rudolph Date: Tue, 3 Dec 2019 19:43:06 +0100 Subject: security: Add common boot media write protection Introduce boot media protection settings and use the existing boot_device_wp_region() function to apply settings on all platforms that supports it yet. Also remove the Intel southbridge code, which is now obsolete. Every platform locks the SPIBAR in a different stage. For align up with the common mrc cache driver and lock after it has been written to. Tested on Supermicro X11SSH-TF. The whole address space is write-protected. Change-Id: Iceb3ecf0bde5cec562bc62d1d5c79da35305d183 Signed-off-by: Patrick Rudolph Reviewed-on: https://review.coreboot.org/c/coreboot/+/32704 Tested-by: build bot (Jenkins) Reviewed-by: Philipp Deppenwiese Reviewed-by: Julius Werner --- src/security/Kconfig | 1 + src/security/Makefile.inc | 1 + src/security/lockdown/Kconfig | 62 ++++++++++++++++++++++++++++++++++++++ src/security/lockdown/Makefile.inc | 6 ++++ src/security/lockdown/lockdown.c | 57 +++++++++++++++++++++++++++++++++++ 5 files changed, 127 insertions(+) create mode 100644 src/security/lockdown/Kconfig create mode 100644 src/security/lockdown/Makefile.inc create mode 100644 src/security/lockdown/lockdown.c (limited to 'src/security') diff --git a/src/security/Kconfig b/src/security/Kconfig index b967311345..65d2defe7d 100644 --- a/src/security/Kconfig +++ b/src/security/Kconfig @@ -15,3 +15,4 @@ source "src/security/vboot/Kconfig" source "src/security/tpm/Kconfig" source "src/security/memory/Kconfig" source "src/security/intel/Kconfig" +source "src/security/lockdown/Kconfig" diff --git a/src/security/Makefile.inc b/src/security/Makefile.inc index fd784385e6..72b87dbe73 100644 --- a/src/security/Makefile.inc +++ b/src/security/Makefile.inc @@ -2,3 +2,4 @@ subdirs-y += vboot subdirs-y += tpm subdirs-y += memory subdirs-y += intel +subdirs-y += lockdown diff --git a/src/security/lockdown/Kconfig b/src/security/lockdown/Kconfig new file mode 100644 index 0000000000..bfdc984b45 --- /dev/null +++ b/src/security/lockdown/Kconfig @@ -0,0 +1,62 @@ + + +choice + prompt "Boot media protection mechanism" + default BOOTMEDIA_LOCK_NONE + +config BOOTMEDIA_LOCK_NONE + bool "Don't lock boot media sections" + +config BOOTMEDIA_LOCK_CONTROLLER + bool "Lock boot media using the controller" + help + Select this if you want the controller to lock specific regions. + This only works on some platforms, please check the code or boot log. + On Intel platforms for e.g. this will make use of the SPIBAR PRRs. + +config BOOTMEDIA_LOCK_CHIP + bool "Lock boot media using the chip" + help + Select this if you want the chip to lock specific regions. + This only works on some chips, please check the code or boot log. + +endchoice + +choice + prompt "Boot media protected regions" + depends on !BOOTMEDIA_LOCK_NONE + default BOOTMEDIA_LOCK_WHOLE_RO + +config BOOTMEDIA_LOCK_WHOLE_RO + bool "Write-protect the whole boot medium" + help + Select this if you want to write-protect the whole firmware boot + medium. + + The locking will take place during the chipset lockdown. + Chipset lockdown is platform specific und might be done unconditionally, + when INTEL_CHIPSET_LOCKDOWN is set or has to be triggered later + (e.g. by the payload or the OS). + + NOTE: If you trigger the chipset lockdown unconditionally, + you won't be able to write to the whole flash chip using the + internal controller any more. + +config BOOTMEDIA_LOCK_WHOLE_NO_ACCESS + depends on BOOTMEDIA_LOCK_CONTROLLER + bool "Read- and write-protect the whole boot medium" + help + Select this if you want to protect the firmware boot medium against + all further accesses. On platforms that memory map a part of the + boot medium the corresponding region is still readable. + + The locking will take place during the chipset lockdown. + Chipset lockdown is platform specific und might be done unconditionally, + when INTEL_CHIPSET_LOCKDOWN is set or has to be triggered later + (e.g. by the payload or the OS). + + NOTE: If you trigger the chipset lockdown unconditionally, + you won't be able to write to the whole flash chip using the + internal controller any more. + +endchoice diff --git a/src/security/lockdown/Makefile.inc b/src/security/lockdown/Makefile.inc new file mode 100644 index 0000000000..a51a106ebc --- /dev/null +++ b/src/security/lockdown/Makefile.inc @@ -0,0 +1,6 @@ +## SPDX-License-Identifier: GPL-2.0-or-later +## This file is part of the coreboot project. + +ifneq ($(CONFIG_BOOTMEDIA_LOCK_NONE),y) +ramstage-y += lockdown.c +endif diff --git a/src/security/lockdown/lockdown.c b/src/security/lockdown/lockdown.c new file mode 100644 index 0000000000..a8aad9b5eb --- /dev/null +++ b/src/security/lockdown/lockdown.c @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* This file is part of the coreboot project. */ + +#include +#include +#include +#include + +/* + * Enables read- /write protection of the bootmedia. + */ +void boot_device_security_lockdown(void) +{ + const struct region_device *rdev; + enum bootdev_prot_type lock_type; + + printk(BIOS_DEBUG, "BM-LOCKDOWN: Enabling boot media protection scheme "); + + if (CONFIG(BOOTMEDIA_LOCK_CONTROLLER)) { + if (CONFIG(BOOTMEDIA_LOCK_WHOLE_RO)) { + printk(BIOS_DEBUG, "'readonly'"); + lock_type = CTRLR_WP; + } else if (CONFIG(BOOTMEDIA_LOCK_WHOLE_NO_ACCESS)) { + printk(BIOS_DEBUG, "'no access'"); + lock_type = CTRLR_RWP; + } + printk(BIOS_DEBUG, "using CTRL...\n"); + } else { + if (CONFIG(BOOTMEDIA_LOCK_WHOLE_RO)) { + printk(BIOS_DEBUG, "'readonly'"); + lock_type = MEDIA_WP; + } + printk(BIOS_DEBUG, "using flash chip...\n"); + } + + rdev = boot_device_ro(); + + if (boot_device_wp_region(rdev, lock_type) >= 0) + printk(BIOS_INFO, "BM-LOCKDOWN: Enabled bootmedia protection\n"); + else + printk(BIOS_ERR, "BM-LOCKDOWN: Failed to enable bootmedia protection\n"); +} + +static void lock(void *unused) +{ + boot_device_security_lockdown(); +} + +/* + * Keep in sync with mrc_cache.c + */ + +#if CONFIG(MRC_WRITE_NV_LATE) +BOOT_STATE_INIT_ENTRY(BS_OS_RESUME_CHECK, BS_ON_EXIT, lock, NULL); +#else +BOOT_STATE_INIT_ENTRY(BS_DEV_RESOURCES, BS_ON_ENTRY, lock, NULL); +#endif -- cgit v1.2.3