diff --git a/src/boot/efi/measure.c b/src/boot/efi/measure.c index 2591c52f22..08a2ecdba8 100644 --- a/src/boot/efi/measure.c +++ b/src/boot/efi/measure.c @@ -187,9 +187,39 @@ bool tpm_present(void) { return tcg2_interface_check(); } -EFI_STATUS tpm_log_event(uint32_t pcrindex, EFI_PHYSICAL_ADDRESS buffer, size_t buffer_size, const char16_t *description, bool *ret_measured) { +static EFI_STATUS tcg2_log_event(uint32_t pcrindex, EFI_PHYSICAL_ADDRESS buffer, size_t buffer_size, const char16_t *description, bool *ret_measured) { EFI_TCG2_PROTOCOL *tpm2; + EFI_STATUS err = EFI_SUCCESS; + + assert(ret_measured); + + tpm2 = tcg2_interface_check(); + if (tpm2) + err = tpm2_measure_to_pcr_and_event_log(tpm2, pcrindex, buffer, buffer_size, description); + + *ret_measured = tpm2 && (err == EFI_SUCCESS); + + return err; +} + +static EFI_STATUS cc_log_event(uint32_t pcrindex, EFI_PHYSICAL_ADDRESS buffer, size_t buffer_size, const char16_t *description, bool *ret_measured) { + EFI_CC_MEASUREMENT_PROTOCOL *cc; + EFI_STATUS err = EFI_SUCCESS; + + assert(ret_measured); + + cc = cc_interface_check(); + if (cc) + err = cc_measure_to_mr_and_event_log(cc, pcrindex, buffer, buffer_size, description); + + *ret_measured = cc && (err == EFI_SUCCESS); + + return err; +} + +EFI_STATUS tpm_log_event(uint32_t pcrindex, EFI_PHYSICAL_ADDRESS buffer, size_t buffer_size, const char16_t *description, bool *ret_measured) { EFI_STATUS err; + bool tpm_ret_measured, cc_ret_measured; assert(description || pcrindex == UINT32_MAX); @@ -203,27 +233,15 @@ EFI_STATUS tpm_log_event(uint32_t pcrindex, EFI_PHYSICAL_ADDRESS buffer, size_t return EFI_SUCCESS; } - tpm2 = tcg2_interface_check(); - if (tpm2) - err = tpm2_measure_to_pcr_and_event_log(tpm2, pcrindex, buffer, buffer_size, description); - else { - EFI_CC_MEASUREMENT_PROTOCOL *cc; + /* Measure into both CC and TPM if both are available to avoid a problem like CVE-2021-42299 */ + err = cc_log_event(pcrindex, buffer, buffer_size, description, &cc_ret_measured); + if (err != EFI_SUCCESS) + return err; - cc = cc_interface_check(); - if (cc) - err = cc_measure_to_mr_and_event_log(cc, pcrindex, buffer, buffer_size, description); - else { - /* No active TPM found, so don't return an error */ - - if (ret_measured) - *ret_measured = false; - - return EFI_SUCCESS; - } - } + err = tcg2_log_event(pcrindex, buffer, buffer_size, description, &tpm_ret_measured); if (err == EFI_SUCCESS && ret_measured) - *ret_measured = true; + *ret_measured = tpm_ret_measured || cc_ret_measured; return err; }