Re: [PATCH v1 7/7] FmpDevicePkg/FmpDxe: Improve function parameter validation

["Michael D Kinney" <michael.d.kinney@intel.com>]

Hi Michael,

A few minor comments included below.  With those updates,

Reviewed-bv: Michael D Kinney <michael.d.kinney@intel.com>

Mike

> -----Original Message-----
> From: michael.kubacki@outlook.com <michael.kubacki@outlook.com>
> Sent: Thursday, July 30, 2020 8:15 PM
> To: devel@edk2.groups.io
> Cc: Gao, Liming <liming.gao@intel.com>; Kinney, Michael D <michael.d.kinney@intel.com>
> Subject: [PATCH v1 7/7] FmpDevicePkg/FmpDxe: Improve function parameter validation
> 
> From: Michael Kubacki <michael.kubacki@microsoft.com>
> 
> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2869
> 
> Makes some minor improvements to function parameter validation
> in FmpDxe, in particular to externally exposed functions such
> as those that back EFI_FIRMWARE_MANAGEMENT_PROTOCOL.
> 
> Cc: Liming Gao <liming.gao@intel.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
> ---
>  FmpDevicePkg/FmpDxe/FmpDxe.c | 56 +++++++++++++++++---
>  FmpDevicePkg/FmpDxe/FmpDxe.h | 10 ++--
>  2 files changed, 54 insertions(+), 12 deletions(-)
> 
> diff --git a/FmpDevicePkg/FmpDxe/FmpDxe.c b/FmpDevicePkg/FmpDxe/FmpDxe.c
> index a3e342591936..958d9b394b71 100644
> --- a/FmpDevicePkg/FmpDxe/FmpDxe.c
> +++ b/FmpDevicePkg/FmpDxe/FmpDxe.c
> @@ -278,6 +278,11 @@ PopulateDescriptor (
>    EFI_STATUS  Status;
>    UINT32      DependenciesSize;
> 
> +  if (Private == NULL) {
> +    DEBUG ((DEBUG_ERROR, "FmpDxe(%s): PopulateDescriptor() - Private is NULL.\n", mImageIdName));
> +    return;
> +  }
> +
>    if (Private->DescriptorPopulated) {
>      return;
>    }
> @@ -429,7 +434,7 @@ PopulateDescriptor (
>    @retval EFI_SUCCESS                The device was successfully updated with the new image.
>    @retval EFI_BUFFER_TOO_SMALL       The ImageInfo buffer was too small. The current buffer size
>                                       needed to hold the image(s) information is returned in ImageInfoSize.
> -  @retval EFI_INVALID_PARAMETER      ImageInfoSize is NULL.
> +  @retval EFI_INVALID_PARAMETER      A required pointer is NULL.
>    @retval EFI_DEVICE_ERROR           Valid information could not be returned. Possible corrupted image.
> 
>  **/
> @@ -451,6 +456,12 @@ GetTheImageInfo (
> 
>    Status = EFI_SUCCESS;
> 
> +  if (This == NULL) {
> +    DEBUG ((DEBUG_ERROR, "FmpDxe(%s): GetImageInfo() - This is NULL.\n", mImageIdName));
> +    Status = EFI_INVALID_PARAMETER;
> +    goto cleanup;
> +  }
> +
>    //
>    // Retrieve the private context structure
>    //
> @@ -536,7 +547,7 @@ GetTheImageInfo (
>    @retval EFI_BUFFER_TOO_SMALL   The buffer specified by ImageSize is too small to hold the
>                                   image. The current buffer size needed to hold the image is returned
>                                   in ImageSize.
> -  @retval EFI_INVALID_PARAMETER  The Image was NULL.
> +  @retval EFI_INVALID_PARAMETER  A required pointer is NULL or ImageIndex is invalid.
>    @retval EFI_NOT_FOUND          The current image is not copied to the buffer.
>    @retval EFI_UNSUPPORTED        The operation is not supported.
>    @retval EFI_SECURITY_VIOLATION The operation could not be performed due to an authentication failure.
> @@ -561,6 +572,12 @@ GetTheImage (
> 
>    Status = EFI_SUCCESS;
> 
> +  if (This == NULL) {
> +    DEBUG ((DEBUG_ERROR, "FmpDxe(%s): GetImage() - This is NULL.\n", mImageIdName));
> +    Status = EFI_INVALID_PARAMETER;
> +    goto cleanup;
> +  }
> +
>    //
>    // Retrieve the private context structure
>    //
> @@ -615,7 +632,8 @@ GetTheImage (
>    @param[in]   Image                 Pointer to the image.
>    @param[in]   ImageSize             Size of the image.
>    @param[in]   AdditionalHeaderSize  Size of any headers that cannot be calculated by this function.
> -  @param[out]  PayloadSize
> +  @param[out]  PayloadSize           An optional pointer to a UINTN that holds the size of the payload
> +                                     (image size minus headers)
> 
>    @retval  !NULL  Valid pointer to the header.
>    @retval  NULL   Structure is bad and pointer cannot be found.
> @@ -626,7 +644,7 @@ GetFmpHeader (
>    IN  CONST EFI_FIRMWARE_IMAGE_AUTHENTICATION  *Image,
>    IN  CONST UINTN                              ImageSize,
>    IN  CONST UINTN                              AdditionalHeaderSize,
> -  OUT UINTN                                    *PayloadSize
> +  OUT UINTN                                    *PayloadSize OPTIONAL
>    )
>  {
>    //
> @@ -640,7 +658,10 @@ GetFmpHeader (
>      return NULL;
>    }
> 
> -  *PayloadSize = ImageSize - (sizeof (Image->MonotonicCount) + Image->AuthInfo.Hdr.dwLength + AdditionalHeaderSize);
> +  if (PayloadSize != NULL) {
> +    *PayloadSize = ImageSize - (sizeof (Image->MonotonicCount) + Image->AuthInfo.Hdr.dwLength + AdditionalHeaderSize);
> +  }
> +
>    return (VOID *)((UINT8 *)Image + sizeof (Image->MonotonicCount) + Image->AuthInfo.Hdr.dwLength  + AdditionalHeaderSize);
>  }
> 
> @@ -663,6 +684,10 @@ GetAllHeaderSize (
>  {
>    UINT32  CalculatedSize;
> 
> +  if (Image == NULL) {

This is an internal helper function.  If Image is ever NULL, it must be a bug in the 
FmpDxe driver.  Should we do more than just return 0?  Perhaps a DEBUG_ERROR message too?

> +    return 0;
> +  }
> +
>    CalculatedSize = sizeof (Image->MonotonicCount) +
>                     AdditionalHeaderSize +
>                     Image->AuthInfo.Hdr.dwLength;
> @@ -698,7 +723,7 @@ GetAllHeaderSize (
> 
>    @retval EFI_SUCCESS            The image was successfully checked.
>    @retval EFI_ABORTED            The operation is aborted.
> -  @retval EFI_INVALID_PARAMETER  The Image was NULL.
> +  @retval EFI_INVALID_PARAMETER  A required pointer is NULL.

This function also uses ImageIndex.  Similar to updates above, I think this
@retval line should be:

  @retval EFI_INVALID_PARAMETER  A required pointer is NULL or ImageIndex is invalid.

>    @retval EFI_UNSUPPORTED        The operation is not supported.
>    @retval EFI_SECURITY_VIOLATION The operation could not be performed due to an authentication failure.
> 
> @@ -743,6 +768,12 @@ CheckTheImage (
>      return EFI_UNSUPPORTED;
>    }
> 
> +  if (This == NULL) {
> +    DEBUG ((DEBUG_ERROR, "FmpDxe(%s): CheckImage() - This is NULL.\n", mImageIdName));
> +    Status = EFI_INVALID_PARAMETER;
> +    goto cleanup;
> +  }
> +
>    //
>    // Retrieve the private context structure
>    //
> @@ -978,7 +1009,7 @@ CheckTheImage (
> 
>    @retval EFI_SUCCESS            The device was successfully updated with the new image.
>    @retval EFI_ABORTED            The operation is aborted.
> -  @retval EFI_INVALID_PARAMETER  The Image was NULL.
> +  @retval EFI_INVALID_PARAMETER  A required pointer is NULL.

This function also uses ImageIndex.  Similar to updates above, I think this
@retval line should be:

  @retval EFI_INVALID_PARAMETER  A required pointer is NULL or ImageIndex is invalid.

>    @retval EFI_UNSUPPORTED        The operation is not supported.
>    @retval EFI_SECURITY_VIOLATION The operation could not be performed due to an authentication failure.
> 
> @@ -1026,6 +1057,12 @@ SetTheImage (
>      return EFI_UNSUPPORTED;
>    }
> 
> +  if (This == NULL) {
> +    DEBUG ((DEBUG_ERROR, "FmpDxe(%s): SetTheImage() - This is NULL.\n", mImageIdName));
> +    Status = EFI_INVALID_PARAMETER;
> +    goto cleanup;
> +  }
> +
>    //
>    // Retrieve the private context structure
>    //
> @@ -1382,6 +1419,11 @@ FmpDxeLockEventNotify (
>    EFI_STATUS                        Status;
>    FIRMWARE_MANAGEMENT_PRIVATE_DATA  *Private;
> 
> +  if (Context == NULL) {
> +    ASSERT (Context != NULL);
> +    return;
> +  }
> +
>    Private = (FIRMWARE_MANAGEMENT_PRIVATE_DATA *)Context;
> 
>    if (!Private->FmpDeviceLocked) {
> diff --git a/FmpDevicePkg/FmpDxe/FmpDxe.h b/FmpDevicePkg/FmpDxe/FmpDxe.h
> index 30754dea495e..4dfec316a558 100644
> --- a/FmpDevicePkg/FmpDxe/FmpDxe.h
> +++ b/FmpDevicePkg/FmpDxe/FmpDxe.h
> @@ -3,7 +3,7 @@
>    image stored in a firmware device with platform and firmware device specific
>    information provided through PCDs and libraries.
> 
> -  Copyright (c) 2016, Microsoft Corporation. All rights reserved.<BR>
> +  Copyright (c) Microsoft Corporation.<BR>
>    Copyright (c) 2018 - 2019, Intel Corporation. All rights reserved.<BR>
> 
>    SPDX-License-Identifier: BSD-2-Clause-Patent
> @@ -132,7 +132,7 @@ DetectTestKey (
>    @retval EFI_SUCCESS                The device was successfully updated with the new image.
>    @retval EFI_BUFFER_TOO_SMALL       The ImageInfo buffer was too small. The current buffer size
>                                       needed to hold the image(s) information is returned in ImageInfoSize.
> -  @retval EFI_INVALID_PARAMETER      ImageInfoSize is NULL.
> +  @retval EFI_INVALID_PARAMETER      A required pointer is NULL.
>    @retval EFI_DEVICE_ERROR           Valid information could not be returned. Possible corrupted image.
> 
>  **/
> @@ -166,7 +166,7 @@ GetTheImageInfo (
>    @retval EFI_BUFFER_TOO_SMALL   The buffer specified by ImageSize is too small to hold the
>                                   image. The current buffer size needed to hold the image is returned
>                                   in ImageSize.
> -  @retval EFI_INVALID_PARAMETER  The Image was NULL.
> +  @retval EFI_INVALID_PARAMETER  A required pointer is NULL or ImageIndex is invalid.
>    @retval EFI_NOT_FOUND          The current image is not copied to the buffer.
>    @retval EFI_UNSUPPORTED        The operation is not supported.
>    @retval EFI_SECURITY_VIOLATION The operation could not be performed due to an authentication failure.
> @@ -198,7 +198,7 @@ GetTheImage (
> 
>    @retval EFI_SUCCESS            The image was successfully checked.
>    @retval EFI_ABORTED            The operation is aborted.
> -  @retval EFI_INVALID_PARAMETER  The Image was NULL.
> +  @retval EFI_INVALID_PARAMETER  A required pointer is NULL.

This function also uses ImageIndex.  Similar to updates above, I think this
@retval line should be:

  @retval EFI_INVALID_PARAMETER  A required pointer is NULL or ImageIndex is invalid.

>    @retval EFI_UNSUPPORTED        The operation is not supported.
>    @retval EFI_SECURITY_VIOLATION The operation could not be performed due to an authentication failure.
> 
> @@ -254,7 +254,7 @@ CheckTheImage (
> 
>    @retval EFI_SUCCESS            The device was successfully updated with the new image.
>    @retval EFI_ABORTED            The operation is aborted.
> -  @retval EFI_INVALID_PARAMETER  The Image was NULL.
> +  @retval EFI_INVALID_PARAMETER  A required pointer is NULL.

This function also uses ImageIndex.  Similar to updates above, I think this
@retval line should be:

  @retval EFI_INVALID_PARAMETER  A required pointer is NULL or ImageIndex is invalid.

>    @retval EFI_UNSUPPORTED        The operation is not supported.
>    @retval EFI_SECURITY_VIOLATION The operation could not be performed due to an authentication failure.
> 
> --
> 2.27.0.windows.1