diff options
Diffstat (limited to 'drivers/char/tpm')
| -rw-r--r-- | drivers/char/tpm/eventlog/acpi.c | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/drivers/char/tpm/eventlog/acpi.c b/drivers/char/tpm/eventlog/acpi.c index 3633ed70f48f..1b18ce5ebab1 100644 --- a/drivers/char/tpm/eventlog/acpi.c +++ b/drivers/char/tpm/eventlog/acpi.c @@ -41,6 +41,27 @@ struct acpi_tcpa { }; }; +/* Check that the given log is indeed a TPM2 log. */ +static bool tpm_is_tpm2_log(void *bios_event_log, u64 len) +{ + struct tcg_efi_specid_event_head *efispecid; + struct tcg_pcr_event *event_header; + int n; + + if (len < sizeof(*event_header)) + return false; + len -= sizeof(*event_header); + event_header = bios_event_log; + + if (len < sizeof(*efispecid)) + return false; + efispecid = (struct tcg_efi_specid_event_head *)event_header->event; + + n = memcmp(efispecid->signature, TCG_SPECID_SIG, + sizeof(TCG_SPECID_SIG)); + return n == 0; +} + /* read binary bios log */ int tpm_read_log_acpi(struct tpm_chip *chip) { @@ -52,6 +73,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip) struct acpi_table_tpm2 *tbl; struct acpi_tpm2_phy *tpm2_phy; int format; + int ret; log = &chip->log; @@ -112,6 +134,7 @@ int tpm_read_log_acpi(struct tpm_chip *chip) log->bios_event_log_end = log->bios_event_log + len; + ret = -EIO; virt = acpi_os_map_iomem(start, len); if (!virt) goto err; @@ -119,11 +142,19 @@ int tpm_read_log_acpi(struct tpm_chip *chip) memcpy_fromio(log->bios_event_log, virt, len); acpi_os_unmap_iomem(virt, len); + + if (chip->flags & TPM_CHIP_FLAG_TPM2 && + !tpm_is_tpm2_log(log->bios_event_log, len)) { + /* try EFI log next */ + ret = -ENODEV; + goto err; + } + return format; err: kfree(log->bios_event_log); log->bios_event_log = NULL; - return -EIO; + return ret; } |