This commit contains the patch files and tests for DxeTpm2MeasureBootLib
CVE 2022-36764.
Cc: Jiewen Yao <jiewen....@intel.com>
Signed-off-by: Doug Flick [MSFT] <doug.e...@gmail.com>
---
.../DxeTpm2MeasureBootLibSanitization.h | 28 ++++++++-
.../DxeTpm2MeasureBootLib.c | 12 ++--
.../DxeTpm2MeasureBootLibSanitization.c | 46 +++++++++++++-
.../DxeTpm2MeasureBootLibSanitizationTest.c | 60 ++++++++++++++++---
4 files changed, 131 insertions(+), 15 deletions(-)
diff --git
a/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.h
b/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLibSanitization.h
index 048b73898744..8f72ba42401f 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/DxeTpm2MeasureBootLib.c
b/SecurityPkg/Library/DxeTpm2MeasureBootLib/DxeTpm2MeasureBootLib.c
index 0475103d6ef8..714cc8e03e80 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 e2309655d384..2a4d52c6d5cf 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/InternalUnitTest/DxeTpm2MeasureBootLibSanitizationTest.c
b/SecurityPkg/Library/DxeTpm2MeasureBootLib/InternalUnitTest/DxeTpm2MeasureBootLibSanitizationTest.c
index 3eb9763e3c91..820e99aeb9b4 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);
--
2.43.0
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