Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751938AbdITIO5 (ORCPT ); Wed, 20 Sep 2017 04:14:57 -0400 Received: from mail-wr0-f202.google.com ([209.85.128.202]:56423 "EHLO mail-wr0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751865AbdITIOP (ORCPT ); Wed, 20 Sep 2017 04:14:15 -0400 X-Google-Smtp-Source: AOwi7QB0PimNAZh90EixVl7/Ef5gwq3SA8NZlaW5NTrvyHZUTrCiI88ZILAvW7XtQIR/N2R2T+Uxaju4MQ== MIME-Version: 1.0 Date: Wed, 20 Sep 2017 10:13:39 +0200 In-Reply-To: <20170920081340.7413-1-tweek@google.com> Message-Id: <20170920081340.7413-5-tweek@google.com> References: <20170920081340.7413-1-tweek@google.com> X-Mailer: git-send-email 2.14.1.821.g8fa685d3b7-goog Subject: [PATCH v3 4/5] efi: call get_event_log before ExitBootServices From: Thiebaud Weksteen To: linux-efi@vger.kernel.org, linux-integrity@vger.kernel.org, tpmdd-devel@lists.sourceforge.net Cc: ard.biesheuvel@linaro.org, matt@codeblueprint.co.uk, linux-kernel@vger.kernel.org, mjg59@google.com, peterhuewe@gmx.de, jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, tpmdd@selhorst.net, Thiebaud Weksteen Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11816 Lines: 332 With TPM 2.0 specification, the event logs may only be accessible by calling an EFI Boot Service. Modify the EFI stub to copy the log area to a new Linux-specific EFI configuration table so it remains accessible once booted. When calling this service, it is possible to specify the expected format of the logs: TPM 1.2 (SHA1) or TPM 2.0 ("Crypto Agile"). For now, only the first format is retrieved. Signed-off-by: Thiebaud Weksteen --- arch/x86/boot/compressed/eboot.c | 1 + drivers/firmware/efi/Makefile | 2 +- drivers/firmware/efi/efi.c | 4 ++ drivers/firmware/efi/libstub/Makefile | 3 +- drivers/firmware/efi/libstub/tpm.c | 81 +++++++++++++++++++++++++++++++++++ drivers/firmware/efi/tpm.c | 40 +++++++++++++++++ include/linux/efi.h | 46 ++++++++++++++++++++ 7 files changed, 174 insertions(+), 3 deletions(-) create mode 100644 drivers/firmware/efi/tpm.c diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c index a1686f3dc295..ef6abe8b3788 100644 --- a/arch/x86/boot/compressed/eboot.c +++ b/arch/x86/boot/compressed/eboot.c @@ -999,6 +999,7 @@ struct boot_params *efi_main(struct efi_config *c, /* Ask the firmware to clear memory on unclean shutdown */ efi_enable_reset_attack_mitigation(sys_table); + efi_retrieve_tpm2_eventlog(sys_table); setup_graphics(boot_params); diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index 0329d319d89a..2f074b5cde87 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -10,7 +10,7 @@ KASAN_SANITIZE_runtime-wrappers.o := n obj-$(CONFIG_ACPI_BGRT) += efi-bgrt.o -obj-$(CONFIG_EFI) += efi.o vars.o reboot.o memattr.o +obj-$(CONFIG_EFI) += efi.o vars.o reboot.o memattr.o tpm.o obj-$(CONFIG_EFI) += capsule.o memmap.o obj-$(CONFIG_EFI_VARS) += efivars.o obj-$(CONFIG_EFI_ESRT) += esrt.o diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index f97f272e16ee..0308acfaaf76 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -52,6 +52,7 @@ struct efi __read_mostly efi = { .properties_table = EFI_INVALID_TABLE_ADDR, .mem_attr_table = EFI_INVALID_TABLE_ADDR, .rng_seed = EFI_INVALID_TABLE_ADDR, + .tpm_log = EFI_INVALID_TABLE_ADDR }; EXPORT_SYMBOL(efi); @@ -444,6 +445,7 @@ static __initdata efi_config_table_type_t common_tables[] = { {EFI_PROPERTIES_TABLE_GUID, "PROP", &efi.properties_table}, {EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table}, {LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed}, + {LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log}, {NULL_GUID, NULL, NULL}, }; @@ -532,6 +534,8 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz, if (efi_enabled(EFI_MEMMAP)) efi_memattr_init(); + efi_tpm_eventlog_init(); + /* Parse the EFI Properties table if it exists */ if (efi.properties_table != EFI_INVALID_TABLE_ADDR) { efi_properties_table_t *tbl; diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index dedf9bde44db..2abe6d22dc5f 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -29,8 +29,7 @@ OBJECT_FILES_NON_STANDARD := y # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in. KCOV_INSTRUMENT := n -lib-y := efi-stub-helper.o gop.o secureboot.o -lib-$(CONFIG_RESET_ATTACK_MITIGATION) += tpm.o +lib-y := efi-stub-helper.o gop.o secureboot.o tpm.o # include the stub's generic dependencies from lib/ when building for ARM/arm64 arm-deps := fdt_rw.c fdt_ro.c fdt_wip.c fdt.c fdt_empty_tree.c fdt_sw.c sort.c diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c index 6224cdbc9669..da661bf8cb96 100644 --- a/drivers/firmware/efi/libstub/tpm.c +++ b/drivers/firmware/efi/libstub/tpm.c @@ -4,15 +4,18 @@ * Copyright (C) 2016 CoreOS, Inc * Copyright (C) 2017 Google, Inc. * Matthew Garrett + * Thiebaud Weksteen * * This file is part of the Linux kernel, and is made available under the * terms of the GNU General Public License version 2. */ #include +#include #include #include "efistub.h" +#ifdef CONFIG_RESET_ATTACK_MITIGATION static const efi_char16_t efi_MemoryOverWriteRequest_name[] = { 'M', 'e', 'm', 'o', 'r', 'y', 'O', 'v', 'e', 'r', 'w', 'r', 'i', 't', 'e', 'R', 'e', 'q', 'u', 'e', 's', 't', 'C', 'o', 'n', 't', 'r', 'o', @@ -56,3 +59,81 @@ void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS, sizeof(val), &val); } + +#endif + +void efi_retrieve_tpm2_eventlog_1_2(efi_system_table_t *sys_table_arg) +{ + efi_guid_t tcg2_guid = EFI_TCG2_PROTOCOL_GUID; + efi_guid_t linux_eventlog_guid = LINUX_EFI_TPM_EVENT_LOG_GUID; + efi_status_t status; + efi_physical_addr_t log_location, log_last_entry; + struct linux_efi_tpm_eventlog *log_tbl; + unsigned long first_entry_addr, last_entry_addr; + size_t log_size, last_entry_size; + efi_bool_t truncated; + void *tcg2_protocol; + + status = efi_call_early(locate_protocol, &tcg2_guid, NULL, + &tcg2_protocol); + if (status != EFI_SUCCESS) + return; + + status = efi_call_proto(efi_tcg2_protocol, get_event_log, tcg2_protocol, + EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2, + &log_location, &log_last_entry, &truncated); + if (status != EFI_SUCCESS) + return; + + if (!log_location) + return; + first_entry_addr = (unsigned long) log_location; + + /* + * We populate the EFI table even if the logs are empty. + */ + if (!log_last_entry) { + log_size = 0; + } else { + last_entry_addr = (unsigned long) log_last_entry; + /* + * get_event_log only returns the address of the last entry. + * We need to calculate its size to deduce the full size of + * the logs. + */ + last_entry_size = sizeof(struct tcpa_event) + + ((struct tcpa_event *) last_entry_addr)->event_size; + log_size = log_last_entry - log_location + last_entry_size; + } + + /* Allocate space for the logs and copy them. */ + status = efi_call_early(allocate_pool, EFI_LOADER_DATA, + sizeof(*log_tbl) + log_size, + (void **) &log_tbl); + + if (status != EFI_SUCCESS) { + efi_printk(sys_table_arg, + "Unable to allocate memory for event log\n"); + return; + } + + memset(log_tbl, 0, sizeof(*log_tbl) + log_size); + log_tbl->size = log_size; + log_tbl->version = EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2; + memcpy(log_tbl->log, (void *) first_entry_addr, log_size); + + status = efi_call_early(install_configuration_table, + &linux_eventlog_guid, log_tbl); + if (status != EFI_SUCCESS) + goto err_free; + return; + +err_free: + efi_call_early(free_pool, log_tbl); +} + +void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table_arg) +{ + /* Only try to retrieve the logs in 1.2 format. */ + efi_retrieve_tpm2_eventlog_1_2(sys_table_arg); +} diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c new file mode 100644 index 000000000000..0cbeb3d46b18 --- /dev/null +++ b/drivers/firmware/efi/tpm.c @@ -0,0 +1,40 @@ +/* + * Copyright (C) 2017 Google, Inc. + * Thiebaud Weksteen + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include + +#include + +/* + * Reserve the memory associated with the TPM Event Log configuration table. + */ +int __init efi_tpm_eventlog_init(void) +{ + struct linux_efi_tpm_eventlog *log_tbl; + unsigned int tbl_size; + + if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) + return 0; + + log_tbl = early_memremap(efi.tpm_log, sizeof(*log_tbl)); + if (!log_tbl) { + pr_err("Failed to map TPM Event Log table @ 0x%lx\n", + efi.tpm_log); + efi.tpm_log = EFI_INVALID_TABLE_ADDR; + return -ENOMEM; + } + + tbl_size = sizeof(*log_tbl) + log_tbl->size; + memblock_reserve(efi.tpm_log, tbl_size); + early_memunmap(log_tbl, sizeof(*log_tbl)); + return 0; +} + diff --git a/include/linux/efi.h b/include/linux/efi.h index 8dc3d94a3e3c..c5805eb601b1 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -472,6 +472,39 @@ typedef struct { u64 get_all; } apple_properties_protocol_64_t; +typedef struct { + u32 get_capability; + u32 get_event_log; + u32 hash_log_extend_event; + u32 submit_command; + u32 get_active_pcr_banks; + u32 set_active_pcr_banks; + u32 get_result_of_set_active_pcr_banks; +} efi_tcg2_protocol_32_t; + +typedef struct { + u64 get_capability; + u64 get_event_log; + u64 hash_log_extend_event; + u64 submit_command; + u64 get_active_pcr_banks; + u64 set_active_pcr_banks; + u64 get_result_of_set_active_pcr_banks; +} efi_tcg2_protocol_64_t; + +typedef u32 efi_tcg2_event_log_format; + +typedef struct { + void *get_capability; + efi_status_t (*get_event_log)(efi_handle_t, efi_tcg2_event_log_format, + efi_physical_addr_t *, efi_physical_addr_t *, efi_bool_t *); + void *hash_log_extend_event; + void *submit_command; + void *get_active_pcr_banks; + void *set_active_pcr_banks; + void *get_result_of_set_active_pcr_banks; +} efi_tcg2_protocol_t; + /* * Types and defines for EFI ResetSystem */ @@ -622,6 +655,7 @@ void efi_native_runtime_setup(void); #define EFI_MEMORY_ATTRIBUTES_TABLE_GUID EFI_GUID(0xdcfa911d, 0x26eb, 0x469f, 0xa2, 0x20, 0x38, 0xb7, 0xdc, 0x46, 0x12, 0x20) #define EFI_CONSOLE_OUT_DEVICE_GUID EFI_GUID(0xd3b36f2c, 0xd551, 0x11d4, 0x9a, 0x46, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d) #define APPLE_PROPERTIES_PROTOCOL_GUID EFI_GUID(0x91bd12fe, 0xf6c3, 0x44fb, 0xa5, 0xb7, 0x51, 0x22, 0xab, 0x30, 0x3a, 0xe0) +#define EFI_TCG2_PROTOCOL_GUID EFI_GUID(0x607f766c, 0x7455, 0x42be, 0x93, 0x0b, 0xe4, 0xd7, 0x6d, 0xb2, 0x72, 0x0f) #define EFI_IMAGE_SECURITY_DATABASE_GUID EFI_GUID(0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f) #define EFI_SHIM_LOCK_GUID EFI_GUID(0x605dab50, 0xe046, 0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23) @@ -634,6 +668,7 @@ void efi_native_runtime_setup(void); #define LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID EFI_GUID(0xe03fc20a, 0x85dc, 0x406e, 0xb9, 0x0e, 0x4a, 0xb5, 0x02, 0x37, 0x1d, 0x95) #define LINUX_EFI_LOADER_ENTRY_GUID EFI_GUID(0x4a67b082, 0x0a4c, 0x41cf, 0xb6, 0xc7, 0x44, 0x0b, 0x29, 0xbb, 0x8c, 0x4f) #define LINUX_EFI_RANDOM_SEED_TABLE_GUID EFI_GUID(0x1ce1e5bc, 0x7ceb, 0x42f2, 0x81, 0xe5, 0x8a, 0xad, 0xf1, 0x80, 0xf5, 0x7b) +#define LINUX_EFI_TPM_EVENT_LOG_GUID EFI_GUID(0xb7799cb0, 0xeca2, 0x4943, 0x96, 0x67, 0x1f, 0xae, 0x07, 0xb7, 0x47, 0xfa) typedef struct { efi_guid_t guid; @@ -908,6 +943,7 @@ extern struct efi { unsigned long properties_table; /* properties table */ unsigned long mem_attr_table; /* memory attributes table */ unsigned long rng_seed; /* UEFI firmware random seed */ + unsigned long tpm_log; /* TPM2 Event Log table */ efi_get_time_t *get_time; efi_set_time_t *set_time; efi_get_wakeup_time_t *get_wakeup_time; @@ -1504,6 +1540,8 @@ static inline void efi_enable_reset_attack_mitigation(efi_system_table_t *sys_table_arg) { } #endif +void efi_retrieve_tpm2_eventlog(efi_system_table_t *sys_table); + /* * Arch code can implement the following three template macros, avoiding * reptition for the void/non-void return cases of {__,}efi_call_virt(): @@ -1571,4 +1609,12 @@ struct linux_efi_random_seed { u8 bits[]; }; +struct linux_efi_tpm_eventlog { + u32 size; + u8 version; + u8 log[]; +}; + +extern int efi_tpm_eventlog_init(void); + #endif /* _LINUX_EFI_H */ -- 2.14.1.821.g8fa685d3b7-goog