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SecurityPkg: Fix Tcg2SubmitCommand in TPM field upgrade scenario #11750

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SecurityPkg: Fix Tcg2SubmitCommand in TPM field upgrade scenario #11750

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62 changes: 51 additions & 11 deletions SecurityPkg/Tcg/Tcg2Dxe/Tcg2Dxe.c
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Original file line number Diff line number Diff line change
Expand Up @@ -81,6 +81,7 @@ typedef struct {

typedef struct _TCG_DXE_DATA {
EFI_TCG2_BOOT_SERVICE_CAPABILITY BsCap;
BOOLEAN TpmUpdateFlag;
TCG_EVENT_LOG_AREA_STRUCT EventLogAreaStruct[TCG_EVENT_LOG_AREA_COUNT_MAX];
BOOLEAN GetEventLogCalled[TCG_EVENT_LOG_AREA_COUNT_MAX];
TCG_EVENT_LOG_AREA_STRUCT FinalEventLogAreaStruct[TCG_EVENT_LOG_AREA_COUNT_MAX];
Expand All @@ -101,6 +102,7 @@ TCG_DXE_DATA mTcgDxeData = {
0, // NumberOfPCRBanks
0, // ActivePcrBanks
},
FALSE,
};

UINTN mBootAttempts = 0;
Expand Down Expand Up @@ -1407,6 +1409,8 @@ Tcg2SubmitCommand (
)
{
EFI_STATUS Status;
TPM_RC ResponseCode;
UINT32 CurrentOutputBlockSize;

if ((This == NULL) ||
(InputParameterBlockSize == 0) || (InputParameterBlock == NULL) ||
Expand All @@ -1415,10 +1419,6 @@ Tcg2SubmitCommand (
return EFI_INVALID_PARAMETER;
}

if (!mTcgDxeData.BsCap.TPMPresentFlag) {
return EFI_DEVICE_ERROR;
}

if (InputParameterBlockSize > mTcgDxeData.BsCap.MaxCommandSize) {
return EFI_INVALID_PARAMETER;
}
Expand All @@ -1427,13 +1427,53 @@ Tcg2SubmitCommand (
return EFI_INVALID_PARAMETER;
}

Status = Tpm2SubmitCommand (
InputParameterBlockSize,
InputParameterBlock,
&OutputParameterBlockSize,
OutputParameterBlock
);
return Status;
//
// Always attempt to submit the command, but if the TPM is already flagged
// as not present, we expect it to fail other than the capsule update scenario.
//
CurrentOutputBlockSize = OutputParameterBlockSize;
Status = Tpm2SubmitCommand (
InputParameterBlockSize,
InputParameterBlock,
&CurrentOutputBlockSize,
OutputParameterBlock
);
if (EFI_ERROR (Status)) {
return mTcgDxeData.BsCap.TPMPresentFlag ? Status : EFI_DEVICE_ERROR;
}

if (CurrentOutputBlockSize < sizeof (TPM2_RESPONSE_HEADER)) {
DEBUG ((DEBUG_ERROR, "%a: Response buffer too small!\n", __func__));
return EFI_DEVICE_ERROR;
}

//
// Correctly read the response code and swap bytes from Big-Endian to Host order.
// The responseCode field is at offset 6 of the response header.
//
ResponseCode = SwapBytes32 (ReadUnaligned32 ((UINT32 *)(OutputParameterBlock + 6)));
DEBUG ((DEBUG_ERROR, "Response code is %x", ResponseCode));
// If the response code ever equals to TPM_RC_UPGRADE, it means the TPM is in field
// upgrade mode, we set both flags to TRUE.
if (ResponseCode == TPM_RC_UPGRADE) {
DEBUG ((DEBUG_INFO, "TPM response code TPM_RC_UPDATE received. Setting flag.\n"));
mTcgDxeData.TpmUpdateFlag = TRUE;
mTcgDxeData.BsCap.TPMPresentFlag = TRUE;
}

// Now that we have set the TPMPresentFlag, it should be able to reflect the actual TPM presence.
if (!mTcgDxeData.BsCap.TPMPresentFlag) {
DEBUG ((DEBUG_WARN, "%a: TPMPresentFlag is FALSE. Expecting command to fail.\n", __func__));
return EFI_DEVICE_ERROR;
}

// If the response code is not TPM_RC_SUCCESS and the device is not in field update mode, return error.
if ((ResponseCode != TPM_RC_SUCCESS) && (mTcgDxeData.TpmUpdateFlag == FALSE)) {
DEBUG ((DEBUG_ERROR, "%a: Command failed with response code 0x%x\n", __func__, ResponseCode));
return EFI_DEVICE_ERROR;
}

return EFI_SUCCESS;
}

/**
Expand Down
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