On Mon, May 20, 2019 at 1:55 PM Matthew Garrett wrote: > > From: Matthew Garrett > > UEFI systems provide a boot services protocol for obtaining the TPM > event log, but this is unusable after ExitBootServices() is called. > Unfortunately ExitBootServices() itself triggers additional TPM events > that then can't be obtained using this protocol. The platform provides a > mechanism for the OS to obtain these events by recording them to a > separate UEFI configuration table which the OS can then map. > > Unfortunately this table isn't self describing in terms of providing its > length, so we need to parse the events inside it to figure out how long > it is. Since the table isn't mapped at this point, we need to extend the > length calculation function to be able to map the event as it goes > along. > > (Fixes by Bartosz Szczepanek ) > > Signed-off-by: Matthew Garrett > --- > drivers/char/tpm/eventlog/tpm2.c | 2 +- > drivers/firmware/efi/efi.c | 2 + > drivers/firmware/efi/tpm.c | 62 ++++++++++++++++++- > include/linux/efi.h | 9 +++ > include/linux/tpm_eventlog.h | 102 ++++++++++++++++++++++++++++--- > 5 files changed, 164 insertions(+), 13 deletions(-) > > diff --git a/drivers/char/tpm/eventlog/tpm2.c b/drivers/char/tpm/eventlog/tpm2.c > index 1a977bdd3bd2..de1d9f7e5a92 100644 > --- a/drivers/char/tpm/eventlog/tpm2.c > +++ b/drivers/char/tpm/eventlog/tpm2.c > @@ -40,7 +40,7 @@ > static size_t calc_tpm2_event_size(struct tcg_pcr_event2_head *event, > struct tcg_pcr_event *event_header) > { > - return __calc_tpm2_event_size(event, event_header); > + return __calc_tpm2_event_size(event, event_header, false); > } > > static void *tpm2_bios_measurements_start(struct seq_file *m, loff_t *pos) > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c > index 55b77c576c42..6b11c41e0575 100644 > --- a/drivers/firmware/efi/efi.c > +++ b/drivers/firmware/efi/efi.c > @@ -53,6 +53,7 @@ struct efi __read_mostly efi = { > .mem_attr_table = EFI_INVALID_TABLE_ADDR, > .rng_seed = EFI_INVALID_TABLE_ADDR, > .tpm_log = EFI_INVALID_TABLE_ADDR, > + .tpm_final_log = EFI_INVALID_TABLE_ADDR, > .mem_reserve = EFI_INVALID_TABLE_ADDR, > }; > EXPORT_SYMBOL(efi); > @@ -485,6 +486,7 @@ static __initdata efi_config_table_type_t common_tables[] = { > {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}, > + {LINUX_EFI_TPM_FINAL_LOG_GUID, "TPMFinalLog", &efi.tpm_final_log}, > {LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &efi.mem_reserve}, > {NULL_GUID, NULL, NULL}, > }; > diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c > index 3a689b40ccc0..2c912ea08166 100644 > --- a/drivers/firmware/efi/tpm.c > +++ b/drivers/firmware/efi/tpm.c > @@ -4,34 +4,90 @@ > * Thiebaud Weksteen > */ > > +#define TPM_MEMREMAP(start, size) early_memremap(start, size) > +#define TPM_MEMUNMAP(start, size) early_memunmap(start, size) > + > #include > #include > #include > +#include > > #include > > +int efi_tpm_final_log_size; > +EXPORT_SYMBOL(efi_tpm_final_log_size); > + > +static int tpm2_calc_event_log_size(void *data, int count, void *size_info) > +{ > + struct tcg_pcr_event2_head *header; > + int event_size, size = 0; > + > + while (count > 0) { > + header = data + size; > + event_size = __calc_tpm2_event_size(header, size_info, true); > + if (event_size == 0) > + return -1; > + size += event_size; > + count--; > + } > + > + return size; > +} > + > /* > * 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; > + struct efi_tcg2_final_events_table *final_tbl; > unsigned int tbl_size; > + int ret = 0; > > - if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) > + if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) { > + /* > + * We can't calculate the size of the final events without the > + * first entry in the TPM log, so bail here. > + */ > 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.tpm_log = EFI_INVALID_TABLE_ADDR; > return -ENOMEM; > } > > tbl_size = sizeof(*log_tbl) + log_tbl->size; > memblock_reserve(efi.tpm_log, tbl_size); > + > + if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) > + goto out; > + > + final_tbl = early_memremap(efi.tpm_final_log, sizeof(*final_tbl)); > + > + if (!final_tbl) { > + pr_err("Failed to map TPM Final Event Log table @ 0x%lx\n", > + efi.tpm_final_log); > + efi.tpm_final_log = EFI_INVALID_TABLE_ADDR; > + ret = -ENOMEM; > + goto out; > + } > + > + tbl_size = tpm2_calc_event_log_size(efi.tpm_final_log > + + sizeof(final_tbl->version) > + + sizeof(final_tbl->nr_events), This line causes: warning: passing argument 1 of ‘tpm2_calc_event_log_size’ makes pointer from integer without a cast > + final_tbl->nr_events, > + log_tbl->log); > + memblock_reserve((unsigned long)final_tbl, > + tbl_size + sizeof(*final_tbl)); > + early_memunmap(final_tbl, sizeof(*final_tbl)); > + efi_tpm_final_log_size = tbl_size; > + > +out: > early_memunmap(log_tbl, sizeof(*log_tbl)); > - return 0; > + return ret; > } > > diff --git a/include/linux/efi.h b/include/linux/efi.h > index 54357a258b35..e33c70a52a9d 100644 > --- a/include/linux/efi.h > +++ b/include/linux/efi.h > @@ -689,6 +689,7 @@ void efi_native_runtime_setup(void); > #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) > +#define LINUX_EFI_TPM_FINAL_LOG_GUID EFI_GUID(0x1e2ed096, 0x30e2, 0x4254, 0xbd, 0x89, 0x86, 0x3b, 0xbe, 0xf8, 0x23, 0x25) > #define LINUX_EFI_MEMRESERVE_TABLE_GUID EFI_GUID(0x888eb0c6, 0x8ede, 0x4ff5, 0xa8, 0xf0, 0x9a, 0xee, 0x5c, 0xb9, 0x77, 0xc2) > > typedef struct { > @@ -996,6 +997,7 @@ extern struct efi { > unsigned long mem_attr_table; /* memory attributes table */ > unsigned long rng_seed; /* UEFI firmware random seed */ > unsigned long tpm_log; /* TPM2 Event Log table */ > + unsigned long tpm_final_log; /* TPM2 Final Events Log table */ > unsigned long mem_reserve; /* Linux EFI memreserve table */ > efi_get_time_t *get_time; > efi_set_time_t *set_time; > @@ -1707,6 +1709,13 @@ struct linux_efi_tpm_eventlog { > > extern int efi_tpm_eventlog_init(void); > > +struct efi_tcg2_final_events_table { > + u64 version; > + u64 nr_events; > + u8 events[]; > +}; > +extern int efi_tpm_final_log_size; > + > /* > * efi_runtime_service() function identifiers. > * "NONE" is used by efi_recover_from_page_fault() to check if the page > diff --git a/include/linux/tpm_eventlog.h b/include/linux/tpm_eventlog.h > index 6a86144e13f1..63238c84dc0b 100644 > --- a/include/linux/tpm_eventlog.h > +++ b/include/linux/tpm_eventlog.h > @@ -112,10 +112,35 @@ struct tcg_pcr_event2_head { > struct tpm_digest digests[]; > } __packed; > > +struct tcg_algorithm_size { > + u16 algorithm_id; > + u16 algorithm_size; > +}; > + > +struct tcg_algorithm_info { > + u8 signature[16]; > + u32 platform_class; > + u8 spec_version_minor; > + u8 spec_version_major; > + u8 spec_errata; > + u8 uintn_size; > + u32 number_of_algorithms; > + struct tcg_algorithm_size digest_sizes[]; > +}; > + > +#ifndef TPM_MEMREMAP > +#define TPM_MEMREMAP(start, size) NULL > +#endif > + > +#ifndef TPM_MEMUNMAP > +#define TPM_MEMUNMAP(start, size) do{} while(0) > +#endif > + > /** > * __calc_tpm2_event_size - calculate the size of a TPM2 event log entry > * @event: Pointer to the event whose size should be calculated > * @event_header: Pointer to the initial event containing the digest lengths > + * @do_mapping: Whether or not the event needs to be mapped > * > * The TPM2 event log format can contain multiple digests corresponding to > * separate PCR banks, and also contains a variable length of the data that > @@ -131,10 +156,13 @@ struct tcg_pcr_event2_head { > */ > > static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event, > - struct tcg_pcr_event *event_header) > + struct tcg_pcr_event *event_header, > + bool do_mapping) > { > struct tcg_efi_specid_event_head *efispecid; > struct tcg_event_field *event_field; > + void *mapping = NULL; > + int mapping_size; > void *marker; > void *marker_start; > u32 halg_size; > @@ -148,16 +176,49 @@ static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event, > marker = marker + sizeof(event->pcr_idx) + sizeof(event->event_type) > + sizeof(event->count); > > + /* Map the event header */ > + if (do_mapping) { > + mapping_size = marker - marker_start; > + mapping = TPM_MEMREMAP((unsigned long)marker_start, > + mapping_size); > + if (!mapping) { > + size = 0; > + goto out; > + } > + } else { > + mapping = marker_start; > + } > + > + event = (struct tcg_pcr_event2_head *)mapping; > + > efispecid = (struct tcg_efi_specid_event_head *)event_header->event; > > /* Check if event is malformed. */ > - if (event->count > efispecid->num_algs) > - return 0; > + if (event->count > efispecid->num_algs) { > + size = 0; > + goto out; > + } > > for (i = 0; i < event->count; i++) { > halg_size = sizeof(event->digests[i].alg_id); > - memcpy(&halg, marker, halg_size); > + > + /* Map the digest's algorithm identifier */ > + if (do_mapping) { > + TPM_MEMUNMAP(mapping, mapping_size); > + mapping_size = halg_size; > + mapping = TPM_MEMREMAP((unsigned long)marker, > + mapping_size); > + if (!mapping) { > + size = 0; > + goto out; > + } > + } else { > + mapping = marker; > + } > + > + memcpy(&halg, mapping, halg_size); > marker = marker + halg_size; > + > for (j = 0; j < efispecid->num_algs; j++) { > if (halg == efispecid->digest_sizes[j].alg_id) { > marker += > @@ -166,18 +227,41 @@ static inline int __calc_tpm2_event_size(struct tcg_pcr_event2_head *event, > } > } > /* Algorithm without known length. Such event is unparseable. */ > - if (j == efispecid->num_algs) > - return 0; > + if (j == efispecid->num_algs) { > + size = 0; > + goto out; > + } > + } > + > + /* > + * Map the event size - we don't read from the event itself, so > + * we don't need to map it > + */ > + if (do_mapping) { > + TPM_MEMUNMAP(mapping, mapping_size); > + mapping_size += sizeof(event_field->event_size); > + mapping = TPM_MEMREMAP((unsigned long)marker, > + mapping_size); > + if (!mapping) { > + size = 0; > + goto out; > + } > + } else { > + mapping = marker; > } > > - event_field = (struct tcg_event_field *)marker; > + event_field = (struct tcg_event_field *)mapping; > + > marker = marker + sizeof(event_field->event_size) > + event_field->event_size; > size = marker - marker_start; > > if ((event->event_type == 0) && (event_field->event_size == 0)) > - return 0; > - > + size = 0; > +out: > + if (do_mapping) > + TPM_MEMUNMAP(mapping, mapping_size); > return size; > } > + > #endif > -- > 2.21.0.1020.gf2820cf01a-goog >