SecurityPkg: DxeTpm2MeasureBootLib: SECURITY PATCH 4118 - CVE 2022-36764

This commit contains the patch files and tests for DxeTpm2MeasureBootLib
CVE 2022-36764.

Cc: Jiewen Yao <jiewen.yao@intel.com>

Signed-off-by: Doug Flick [MSFT] <doug.edk2@gmail.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

4 files changed, 131 insertions, 15 deletions

diff --git a/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLib.c b/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLib.c
index 0475103..714cc8e 100644
--- a/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLib.c
+++ b/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLib.c
@@ -378,7 +378,6 @@ Exit:
   @retval EFI_OUT_OF_RESOURCES   No enough resource to measure image.

   @retval EFI_UNSUPPORTED        ImageType is unsupported or PE image is mal-format.

   @retval other error value

-

 **/

 EFI_STATUS

 EFIAPI

@@ -405,6 +404,7 @@ Tcg2MeasurePeImage (
   Status    = EFI_UNSUPPORTED;

   ImageLoad = NULL;

   EventPtr  = NULL;

+  Tcg2Event = NULL;

 

   Tcg2Protocol = MeasureBootProtocols->Tcg2Protocol;

   CcProtocol   = MeasureBootProtocols->CcProtocol;

@@ -420,18 +420,22 @@ Tcg2MeasurePeImage (
   }

 

   FilePathSize = (UINT32)GetDevicePathSize (FilePath);

+  Status       = SanitizePeImageEventSize (FilePathSize, &EventSize);

+  if (EFI_ERROR (Status)) {

+    return EFI_UNSUPPORTED;

+  }

 

   //

   // Determine destination PCR by BootPolicy

   //

-  EventSize = sizeof (*ImageLoad) - sizeof (ImageLoad->DevicePath) + FilePathSize;

-  EventPtr  = AllocateZeroPool (EventSize + sizeof (EFI_TCG2_EVENT) - sizeof (Tcg2Event->Event));

+  // from a malicious GPT disk partition

+  EventPtr = AllocateZeroPool (EventSize);

   if (EventPtr == NULL) {

     return EFI_OUT_OF_RESOURCES;

   }

 

   Tcg2Event                       = (EFI_TCG2_EVENT *)EventPtr;

-  Tcg2Event->Size                 = EventSize + sizeof (EFI_TCG2_EVENT) - sizeof (Tcg2Event->Event);

+  Tcg2Event->Size                 = EventSize;

   Tcg2Event->Header.HeaderSize    = sizeof (EFI_TCG2_EVENT_HEADER);

   Tcg2Event->Header.HeaderVersion = EFI_TCG2_EVENT_HEADER_VERSION;

   ImageLoad                       = (EFI_IMAGE_LOAD_EVENT *)Tcg2Event->Event;

diff --git a/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.c b/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.c
index e230965..2a4d52c 100644
--- a/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.c
+++ b/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.c
@@ -151,7 +151,7 @@ SanitizeEfiPartitionTableHeader (
 }

 

 /**

-  This function will validate that the allocation size from the primary header is sane

+ This function will validate that the allocation size from the primary header is sane

   It will check the following:

     - AllocationSize does not overflow

 

@@ -273,3 +273,47 @@ SanitizePrimaryHeaderGptEventSize (
 

   return EFI_SUCCESS;

 }

+

+/**

+  This function will validate that the PeImage Event Size from the loaded image is sane

+  It will check the following:

+    - EventSize does not overflow

+

+  @param[in] FilePathSize - Size of the file path.

+  @param[out] EventSize - Pointer to the event size.

+

+  @retval EFI_SUCCESS

+    The event size is valid.

+

+  @retval EFI_OUT_OF_RESOURCES

+    Overflow would have occurred.

+

+  @retval EFI_INVALID_PARAMETER

+    One of the passed parameters was invalid.

+**/

+EFI_STATUS

+SanitizePeImageEventSize (

+  IN  UINT32  FilePathSize,

+  OUT UINT32  *EventSize

+  )

+{

+  EFI_STATUS  Status;

+

+  // Replacing logic:

+  // sizeof (*ImageLoad) - sizeof (ImageLoad->DevicePath) + FilePathSize;

+  Status = SafeUint32Add (OFFSET_OF (EFI_IMAGE_LOAD_EVENT, DevicePath), FilePathSize, EventSize);

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "EventSize would overflow!\n"));

+    return EFI_BAD_BUFFER_SIZE;

+  }

+

+  // Replacing logic:

+  // EventSize + sizeof (EFI_TCG2_EVENT) - sizeof (Tcg2Event->Event)

+  Status = SafeUint32Add (*EventSize, OFFSET_OF (EFI_TCG2_EVENT, Event), EventSize);

+  if (EFI_ERROR (Status)) {

+    DEBUG ((DEBUG_ERROR, "EventSize would overflow!\n"));

+    return EFI_BAD_BUFFER_SIZE;

+  }

+

+  return EFI_SUCCESS;

+}

diff --git a/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.h b/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.h
index 048b738..8f72ba4 100644
--- a/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.h
+++ b/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.h
@@ -9,6 +9,9 @@
   Tcg2MeasureGptTable() function will receive untrusted GPT partition table, and parse

   partition data carefully.

 

+  Tcg2MeasurePeImage() function will accept untrusted PE/COFF image and validate its

+  data structure within this image buffer before use.

+

   Copyright (c) Microsoft Corporation.<BR>

   SPDX-License-Identifier: BSD-2-Clause-Patent

 

@@ -110,4 +113,27 @@ SanitizePrimaryHeaderGptEventSize (
   OUT UINT32                            *EventSize

   );

 

-#endif // DXE_TPM2_MEASURE_BOOT_LIB_SANITATION_

+/**

+  This function will validate that the PeImage Event Size from the loaded image is sane

+  It will check the following:

+    - EventSize does not overflow

+

+  @param[in] FilePathSize - Size of the file path.

+  @param[out] EventSize - Pointer to the event size.

+

+  @retval EFI_SUCCESS

+    The event size is valid.

+

+  @retval EFI_OUT_OF_RESOURCES

+    Overflow would have occurred.

+

+  @retval EFI_INVALID_PARAMETER

+    One of the passed parameters was invalid.

+**/

+EFI_STATUS

+SanitizePeImageEventSize (

+  IN  UINT32  FilePathSize,

+  OUT UINT32  *EventSize

+  );

+

+#endif // DXE_TPM2_MEASURE_BOOT_LIB_VALIDATION_

diff --git a/SecurityPkg/Library/DxeTpm2MeasureBootLib/InternalUnitTest/DxeTpm2MeasureBootLibSanitizationTest.c b/SecurityPkg/Library/DxeTpm2MeasureBootLib/InternalUnitTest/DxeTpm2MeasureBootLibSanitizationTest.c
index 3eb9763..820e99a 100644
--- a/SecurityPkg/Library/DxeTpm2MeasureBootLib/InternalUnitTest/DxeTpm2MeasureBootLibSanitizationTest.c
+++ b/SecurityPkg/Library/DxeTpm2MeasureBootLib/InternalUnitTest/DxeTpm2MeasureBootLibSanitizationTest.c
@@ -72,10 +72,10 @@ TestSanitizeEfiPartitionTableHeader (
   PrimaryHeader.Header.Revision          = DEFAULT_PRIMARY_TABLE_HEADER_REVISION;

   PrimaryHeader.Header.HeaderSize        = sizeof (EFI_PARTITION_TABLE_HEADER);

   PrimaryHeader.MyLBA                    = 1;

-  PrimaryHeader.AlternateLBA             = 2;

-  PrimaryHeader.FirstUsableLBA           = 3;

-  PrimaryHeader.LastUsableLBA            = 4;

-  PrimaryHeader.PartitionEntryLBA        = 5;

+  PrimaryHeader.PartitionEntryLBA        = 2;

+  PrimaryHeader.AlternateLBA             = 3;

+  PrimaryHeader.FirstUsableLBA           = 4;

+  PrimaryHeader.LastUsableLBA            = 5;

   PrimaryHeader.NumberOfPartitionEntries = DEFAULT_PRIMARY_TABLE_HEADER_NUMBER_OF_PARTITION_ENTRIES;

   PrimaryHeader.SizeOfPartitionEntry     = DEFAULT_PRIMARY_TABLE_HEADER_SIZE_OF_PARTITION_ENTRY;

   PrimaryHeader.PartitionEntryArrayCRC32 = 0; // Purposely invalid

@@ -187,11 +187,6 @@ TestSanitizePrimaryHeaderGptEventSize (
   EFI_STATUS                  Status;

   EFI_PARTITION_TABLE_HEADER  PrimaryHeader;

   UINTN                       NumberOfPartition;

-  EFI_GPT_DATA                *GptData;

-  EFI_TCG2_EVENT              *Tcg2Event;

-

-  Tcg2Event = NULL;

-  GptData   = NULL;

 

   // Test that a normal PrimaryHeader passes validation

   PrimaryHeader.NumberOfPartitionEntries = 5;

@@ -225,6 +220,52 @@ TestSanitizePrimaryHeaderGptEventSize (
   return UNIT_TEST_PASSED;

 }

 

+/**

+  This function tests the SanitizePeImageEventSize function.

+  It's intent is to test that the untrusted input from a file path when generating a

+  EFI_IMAGE_LOAD_EVENT structure will not cause an overflow when calculating

+  the event size when allocating space

+

+  @param[in] Context  The unit test context.

+

+  @retval UNIT_TEST_PASSED  The test passed.

+  @retval UNIT_TEST_ERROR_TEST_FAILED  The test failed.

+**/

+UNIT_TEST_STATUS

+EFIAPI

+TestSanitizePeImageEventSize (

+  IN UNIT_TEST_CONTEXT  Context

+  )

+{

+  UINT32      EventSize;

+  UINTN       ExistingLogicEventSize;

+  UINT32      FilePathSize;

+  EFI_STATUS  Status;

+

+  FilePathSize = 255;

+

+  // Test that a normal PE image passes validation

+  Status = SanitizePeImageEventSize (FilePathSize, &EventSize);

+  UT_ASSERT_EQUAL (Status, EFI_SUCCESS);

+

+  // Test that the event size is correct compared to the existing logic

+  ExistingLogicEventSize  = OFFSET_OF (EFI_IMAGE_LOAD_EVENT, DevicePath) + FilePathSize;

+  ExistingLogicEventSize += OFFSET_OF (EFI_TCG2_EVENT, Event);

+

+  if (EventSize != ExistingLogicEventSize) {

+    UT_LOG_ERROR ("SanitizePeImageEventSize returned an incorrect event size. Expected %u, got %u\n", ExistingLogicEventSize, EventSize);

+    return UNIT_TEST_ERROR_TEST_FAILED;

+  }

+

+  // Test that the event size may not overflow

+  Status = SanitizePeImageEventSize (MAX_UINT32, &EventSize);

+  UT_ASSERT_EQUAL (Status, EFI_BAD_BUFFER_SIZE);

+

+  DEBUG ((DEBUG_INFO, "%a: Test passed\n", __func__));

+

+  return UNIT_TEST_PASSED;

+}

+

 // *--------------------------------------------------------------------*

 // *  Unit Test Code Main Function

 // *--------------------------------------------------------------------*

@@ -267,6 +308,7 @@ UefiTestMain (
   AddTestCase (Tcg2MeasureBootLibValidationTestSuite, "Tests Validating EFI Partition Table", "Common.Tcg2MeasureBootLibValidation", TestSanitizeEfiPartitionTableHeader, NULL, NULL, NULL);

   AddTestCase (Tcg2MeasureBootLibValidationTestSuite, "Tests Primary header gpt event checks for overflow", "Common.Tcg2MeasureBootLibValidation", TestSanitizePrimaryHeaderAllocationSize, NULL, NULL, NULL);

   AddTestCase (Tcg2MeasureBootLibValidationTestSuite, "Tests Primary header allocation size checks for overflow", "Common.Tcg2MeasureBootLibValidation", TestSanitizePrimaryHeaderGptEventSize, NULL, NULL, NULL);

+  AddTestCase (Tcg2MeasureBootLibValidationTestSuite, "Tests PE Image and FileSize checks for overflow", "Common.Tcg2MeasureBootLibValidation", TestSanitizePeImageEventSize, NULL, NULL, NULL);

 

   Status = RunAllTestSuites (Framework);