From fe7eb0230c3dd95c947e18248808d7038c65f43e Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Mon, 20 May 2019 13:55:00 -0700 Subject: [PATCH] tpm: Append the final event log to the TPM event log Any events that are logged after GetEventsLog() is called are logged to the EFI Final Events table. These events are defined as being in the crypto agile log format, so we can just append them directly to the existing log if it's in the same format. In theory we can also construct old-style SHA1 log entries for devices that only return logs in that format, but EDK2 doesn't generate the final event log in that case so it doesn't seem worth it at the moment. Signed-off-by: Matthew Garrett Reviewed-by: Bartosz Szczepanek Tested-by: Bartosz Szczepanek Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/eventlog/efi.c | 50 ++++++++++++++++++++++++++++----- 1 file changed, 43 insertions(+), 7 deletions(-) diff --git a/drivers/char/tpm/eventlog/efi.c b/drivers/char/tpm/eventlog/efi.c index 3e44362e469c..73b981026627 100644 --- a/drivers/char/tpm/eventlog/efi.c +++ b/drivers/char/tpm/eventlog/efi.c @@ -16,10 +16,13 @@ int tpm_read_log_efi(struct tpm_chip *chip) { + struct efi_tcg2_final_events_table *final_tbl = NULL; struct linux_efi_tpm_eventlog *log_tbl; struct tpm_bios_log *log; u32 log_size; u8 tpm_log_version; + void *tmp; + int ret; if (!(chip->flags & TPM_CHIP_FLAG_TPM2)) return -ENODEV; @@ -47,15 +50,48 @@ int tpm_read_log_efi(struct tpm_chip *chip) /* malloc EventLog space */ log->bios_event_log = kmemdup(log_tbl->log, log_size, GFP_KERNEL); - if (!log->bios_event_log) - goto err_memunmap; + if (!log->bios_event_log) { + ret = -ENOMEM; + goto out; + } + log->bios_event_log_end = log->bios_event_log + log_size; - tpm_log_version = log_tbl->version; - memunmap(log_tbl); - return tpm_log_version; -err_memunmap: + ret = tpm_log_version; + + if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR || + efi_tpm_final_log_size == 0 || + tpm_log_version != EFI_TCG2_EVENT_LOG_FORMAT_TCG_2) + goto out; + + final_tbl = memremap(efi.tpm_final_log, + sizeof(*final_tbl) + efi_tpm_final_log_size, + MEMREMAP_WB); + if (!final_tbl) { + pr_err("Could not map UEFI TPM final log\n"); + kfree(log->bios_event_log); + ret = -ENOMEM; + goto out; + } + + tmp = krealloc(log->bios_event_log, + log_size + efi_tpm_final_log_size, + GFP_KERNEL); + if (!tmp) { + kfree(log->bios_event_log); + ret = -ENOMEM; + goto out; + } + + log->bios_event_log = tmp; + memcpy((void *)log->bios_event_log + log_size, + final_tbl->events, efi_tpm_final_log_size); + log->bios_event_log_end = log->bios_event_log + + log_size + efi_tpm_final_log_size; + +out: + memunmap(final_tbl); memunmap(log_tbl); - return -ENOMEM; + return ret; }