[PATCH edk2 v1 3/3] StandaloneMmPkg: Fix check buffer address failed issue from TF-A


Ming Huang
 

There are two scene communicate with StandaloneMm(MM):
1 edk2 -> TF-A -> MM, communicate MM use non-secure buffer which
specify by EFI_SECURE_PARTITION_BOOT_INFO.SpNsCommBufBase;
2 RAS scene: fiq -> TF-A -> MM, use secure buffer which
specify by EFI_SECURE_PARTITION_BOOT_INFO.SpShareBufBase;

For now, the second scene will failed because check buffer address.
This patch add CheckBufferAddr() to support check address for secure
buffer.

Signed-off-by: Ming Huang <huangming@linux.alibaba.com>
---
StandaloneMmPkg/Drivers/StandaloneMmCpu/EventHandle.c | 70 ++++++++++++++++----
StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.c | 21 ++++++
StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.h | 1 +
3 files changed, 79 insertions(+), 13 deletions(-)

diff --git a/StandaloneMmPkg/Drivers/StandaloneMmCpu/EventHandle.c b/StandaloneMmPkg/Drivers/StandaloneMmCpu/EventHandle.c
index 5dfaf9d751..63fab1bd78 100644
--- a/StandaloneMmPkg/Drivers/StandaloneMmCpu/EventHandle.c
+++ b/StandaloneMmPkg/Drivers/StandaloneMmCpu/EventHandle.c
@@ -50,6 +50,7 @@ EFI_MM_COMMUNICATE_HEADER **PerCpuGuidedEventContext = NULL;

// Descriptor with whereabouts of memory used for communication with the normal world
EFI_MMRAM_DESCRIPTOR mNsCommBuffer;
+EFI_MMRAM_DESCRIPTOR mSCommBuffer;

MP_INFORMATION_HOB_DATA *mMpInformationHobData;

@@ -60,6 +61,58 @@ EFI_MM_CONFIGURATION_PROTOCOL mMmConfig = {

STATIC EFI_MM_ENTRY_POINT mMmEntryPoint = NULL;

+STATIC
+EFI_STATUS
+CheckBufferAddr (
+ IN UINTN CommBufferAddr
+ )
+{
+ UINTN CommBufferSize;
+ EFI_STATUS Status;
+
+ Status = EFI_SUCCESS;
+ if (CommBufferAddr < mNsCommBuffer.PhysicalStart) {
+ Status = EFI_ACCESS_DENIED;
+ }
+
+ if ((CommBufferAddr + sizeof (EFI_MM_COMMUNICATE_HEADER)) >=
+ (mNsCommBuffer.PhysicalStart + mNsCommBuffer.PhysicalSize)) {
+ Status = EFI_INVALID_PARAMETER;
+ }
+
+ // Find out the size of the buffer passed
+ CommBufferSize = ((EFI_MM_COMMUNICATE_HEADER *) CommBufferAddr)->MessageLength +
+ sizeof (EFI_MM_COMMUNICATE_HEADER);
+
+ // perform bounds check.
+ if (CommBufferAddr + CommBufferSize >=
+ mNsCommBuffer.PhysicalStart + mNsCommBuffer.PhysicalSize) {
+ Status = EFI_ACCESS_DENIED;
+ }
+
+ if (!EFI_ERROR (Status)) {
+ return EFI_SUCCESS;
+ }
+
+ Status = EFI_SUCCESS;
+ if (CommBufferAddr < mSCommBuffer.PhysicalStart) {
+ Status = EFI_ACCESS_DENIED;
+ }
+
+ if ((CommBufferAddr + sizeof (EFI_MM_COMMUNICATE_HEADER)) >=
+ (mSCommBuffer.PhysicalStart + mSCommBuffer.PhysicalSize)) {
+ Status = EFI_INVALID_PARAMETER;
+ }
+
+ // perform bounds check.
+ if (CommBufferAddr + CommBufferSize >=
+ mSCommBuffer.PhysicalStart + mSCommBuffer.PhysicalSize) {
+ Status = EFI_ACCESS_DENIED;
+ }
+
+ return Status;
+}
+
/**
The PI Standalone MM entry point for the TF-A CPU driver.

@@ -104,25 +157,16 @@ PiMmStandaloneArmTfCpuDriverEntry (
return EFI_INVALID_PARAMETER;
}

- if (NsCommBufferAddr < mNsCommBuffer.PhysicalStart) {
- return EFI_ACCESS_DENIED;
- }
-
- if ((NsCommBufferAddr + sizeof (EFI_MM_COMMUNICATE_HEADER)) >=
- (mNsCommBuffer.PhysicalStart + mNsCommBuffer.PhysicalSize)) {
- return EFI_INVALID_PARAMETER;
+ Status = CheckBufferAddr (NsCommBufferAddr);
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "Check Buffer failed: %r\n", Status));
+ return Status;
}

// Find out the size of the buffer passed
NsCommBufferSize = ((EFI_MM_COMMUNICATE_HEADER *) NsCommBufferAddr)->MessageLength +
sizeof (EFI_MM_COMMUNICATE_HEADER);

- // perform bounds check.
- if (NsCommBufferAddr + NsCommBufferSize >=
- mNsCommBuffer.PhysicalStart + mNsCommBuffer.PhysicalSize) {
- return EFI_ACCESS_DENIED;
- }
-
GuidedEventContext = NULL;
// Now that the secure world can see the normal world buffer, allocate
// memory to copy the communication buffer to the secure world.
diff --git a/StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.c b/StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.c
index fd9c59b4da..96dad20dd1 100644
--- a/StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.c
+++ b/StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.c
@@ -107,6 +107,7 @@ StandaloneMmCpuInitialize (
UINTN Index;
UINTN ArraySize;
VOID *HobStart;
+ EFI_MMRAM_HOB_DESCRIPTOR_BLOCK *MmramRangesHob;

ASSERT (SystemTable != NULL);
mMmst = SystemTable;
@@ -186,6 +187,26 @@ StandaloneMmCpuInitialize (
CopyMem (&mNsCommBuffer, NsCommBufMmramRange, sizeof(EFI_MMRAM_DESCRIPTOR));
DEBUG ((DEBUG_INFO, "mNsCommBuffer: 0x%016lx - 0x%lx\n", mNsCommBuffer.CpuStart, mNsCommBuffer.PhysicalSize));

+ Status = GetGuidedHobData (
+ HobStart,
+ &gEfiMmPeiMmramMemoryReserveGuid,
+ (VOID **) &MmramRangesHob
+ );
+ if (EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "MmramRangesHob data extraction failed - 0x%x\n", Status));
+ return Status;
+ }
+
+ //
+ // As CreateHobListFromBootInfo(), the base and size of buffer shared with
+ // privileged Secure world software is in second one.
+ //
+ CopyMem (
+ &mSCommBuffer,
+ &MmramRangesHob->Descriptor[0] + 1,
+ sizeof(EFI_MMRAM_DESCRIPTOR)
+ );
+
//
// Extract the MP information from the Hoblist
//
diff --git a/StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.h b/StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.h
index 2c96439c15..2e03b20d85 100644
--- a/StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.h
+++ b/StandaloneMmPkg/Drivers/StandaloneMmCpu/StandaloneMmCpu.h
@@ -30,6 +30,7 @@ extern EFI_MM_CPU_PROTOCOL mMmCpuState;
//
extern EFI_MM_COMMUNICATE_HEADER **PerCpuGuidedEventContext;
extern EFI_MMRAM_DESCRIPTOR mNsCommBuffer;
+extern EFI_MMRAM_DESCRIPTOR mSCommBuffer;
extern MP_INFORMATION_HOB_DATA *mMpInformationHobData;
extern EFI_MM_CONFIGURATION_PROTOCOL mMmConfig;

--
2.17.1

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