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/include/boot_device.h | 8 +++++ 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 ++++++++++++++++++++++++++++++ src/southbridge/intel/common/Kconfig | 39 --------------------- src/southbridge/intel/common/finalize.c | 10 ------ 8 files changed, 135 insertions(+), 49 deletions(-) create mode 100644 src/security/lockdown/Kconfig create mode 100644 src/security/lockdown/Makefile.inc create mode 100644 src/security/lockdown/lockdown.c diff --git a/src/include/boot_device.h b/src/include/boot_device.h index 4707331ce6..31464624b9 100644 --- a/src/include/boot_device.h +++ b/src/include/boot_device.h @@ -62,4 +62,12 @@ int boot_device_wp_region(const struct region_device *rd, **/ void boot_device_init(void); +/* + * Restrict read/write access to the bootmedia using platform defined rules. + */ +#if CONFIG(BOOTMEDIA_LOCK_NONE) +static inline void boot_device_security_lockdown(void) {} +#else +void boot_device_security_lockdown(void); +#endif #endif /* _BOOT_DEVICE_H_ */ 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 diff --git a/src/southbridge/intel/common/Kconfig b/src/southbridge/intel/common/Kconfig index d1b6bf6024..9356a2be16 100644 --- a/src/southbridge/intel/common/Kconfig +++ b/src/southbridge/intel/common/Kconfig @@ -97,42 +97,3 @@ config INTEL_CHIPSET_LOCKDOWN config SOUTHBRIDGE_INTEL_COMMON_WATCHDOG bool depends on SOUTHBRIDGE_INTEL_COMMON_PMBASE - -if SOUTHBRIDGE_INTEL_COMMON_FINALIZE - -choice - prompt "Flash locking during chipset lockdown" - default LOCK_SPI_FLASH_NONE - -config LOCK_SPI_FLASH_NONE - bool "Don't lock flash sections" - -config LOCK_SPI_FLASH_RO - bool "Write-protect all flash sections" - help - Select this if you want to write-protect the whole firmware flash - chip. The locking will take place during the chipset lockdown, which - is either triggered by coreboot (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 flash chip using the - internal programmer any more. - -config LOCK_SPI_FLASH_NO_ACCESS - bool "Write-protect all flash sections and read-protect non-BIOS sections" - help - Select this if you want to protect the firmware flash against all - further accesses (with the exception of the memory mapped BIOS re- - gion which is always readable). The locking will take place during - the chipset lockdown, which is either triggered by coreboot (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 flash chip using the - internal programmer any more. - -endchoice - -endif diff --git a/src/southbridge/intel/common/finalize.c b/src/southbridge/intel/common/finalize.c index 4c6cc63466..2d66cad89c 100644 --- a/src/southbridge/intel/common/finalize.c +++ b/src/southbridge/intel/common/finalize.c @@ -15,16 +15,6 @@ void intel_pch_finalize_smm(void) { const pci_devfn_t lpc_dev = PCI_DEV(0, 0x1f, 0); - if (CONFIG(LOCK_SPI_FLASH_RO) || - CONFIG(LOCK_SPI_FLASH_NO_ACCESS)) { - int i; - u32 lockmask = 1UL << 31; - if (CONFIG(LOCK_SPI_FLASH_NO_ACCESS)) - lockmask |= 1 << 15; - for (i = 0; i < 20; i += 4) - RCBA32(0x3874 + i) = RCBA32(0x3854 + i) | lockmask; - } - /* Lock SPIBAR */ RCBA32_OR(0x3804, (1 << 15)); -- cgit v1.2.3