[edk2-devel] [PATCH v3 1/4] UefiPayloadPkg/Hob: Integer Overflow in CreateHob()

["Guo, Gua" <gua.guo@intel.com>]

From: Gua Guo <gua.guo@intel.com>

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4166

Fix integer overflow in various CreateHob instances.
Fixes: CVE-2022-36765

The CreateHob() function aligns the requested size to 8
performing the following operation:
```
HobLength = (UINT16)((HobLength + 0x7) & (~0x7));
```

No checks are performed to ensure this value doesn't
overflow, and could lead to CreateHob() returning a smaller
HOB than requested, which could lead to OOB HOB accesses.

Reported-by: Marc Beatove <mbeatove@google.com>
Cc: Guo Dong <guo.dong@intel.com>
Cc: Sean Rhodes <sean@starlabs.systems>
Cc: James Lu <james.lu@intel.com>
Reviewed-by: Gua Guo <gua.guo@intel.com>
Cc: John Mathew <john.mathews@intel.com>
Authored-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Gua Guo <gua.guo@intel.com>
---
 .../Library/PayloadEntryHobLib/Hob.c          | 43 +++++++++++++++++++
 .../FitUniversalPayloadEntry.c                |  8 ++--
 .../UefiPayloadEntry/UniversalPayloadEntry.c  |  8 ++--
 3 files changed, 53 insertions(+), 6 deletions(-)

diff --git a/UefiPayloadPkg/Library/PayloadEntryHobLib/Hob.c b/UefiPayloadPkg/Library/PayloadEntryHobLib/Hob.c
index 2c3acbbc19..51c2e28d7d 100644
--- a/UefiPayloadPkg/Library/PayloadEntryHobLib/Hob.c
+++ b/UefiPayloadPkg/Library/PayloadEntryHobLib/Hob.c
@@ -110,6 +110,13 @@ CreateHob (
 
   HandOffHob = GetHobList ();
 
+  //
+  // Check Length to avoid data overflow.
+  //
+  if (HobLength > MAX_UINT16 - 0x7) {
+    return NULL;
+  }
+
   HobLength = (UINT16)((HobLength + 0x7) & (~0x7));
 
   FreeMemory = HandOffHob->EfiFreeMemoryTop - HandOffHob->EfiFreeMemoryBottom;
@@ -160,6 +167,9 @@ BuildResourceDescriptorHob (
 
   Hob = CreateHob (EFI_HOB_TYPE_RESOURCE_DESCRIPTOR, sizeof (EFI_HOB_RESOURCE_DESCRIPTOR));
   ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return;
+  }
 
   Hob->ResourceType      = ResourceType;
   Hob->ResourceAttribute = ResourceAttribute;
@@ -330,6 +340,10 @@ BuildModuleHob (
     );
 
   Hob = CreateHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, sizeof (EFI_HOB_MEMORY_ALLOCATION_MODULE));
+  ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return;
+  }
 
   CopyGuid (&(Hob->MemoryAllocationHeader.Name), &gEfiHobMemoryAllocModuleGuid);
   Hob->MemoryAllocationHeader.MemoryBaseAddress = MemoryAllocationModule;
@@ -378,6 +392,11 @@ BuildGuidHob (
   ASSERT (DataLength <= (0xffff - sizeof (EFI_HOB_GUID_TYPE)));
 
   Hob = CreateHob (EFI_HOB_TYPE_GUID_EXTENSION, (UINT16)(sizeof (EFI_HOB_GUID_TYPE) + DataLength));
+  ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return NULL;
+  }
+
   CopyGuid (&Hob->Name, Guid);
   return Hob + 1;
 }
@@ -441,6 +460,10 @@ BuildFvHob (
   EFI_HOB_FIRMWARE_VOLUME  *Hob;
 
   Hob = CreateHob (EFI_HOB_TYPE_FV, sizeof (EFI_HOB_FIRMWARE_VOLUME));
+  ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return;
+  }
 
   Hob->BaseAddress = BaseAddress;
   Hob->Length      = Length;
@@ -472,6 +495,10 @@ BuildFv2Hob (
   EFI_HOB_FIRMWARE_VOLUME2  *Hob;
 
   Hob = CreateHob (EFI_HOB_TYPE_FV2, sizeof (EFI_HOB_FIRMWARE_VOLUME2));
+  ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return;
+  }
 
   Hob->BaseAddress = BaseAddress;
   Hob->Length      = Length;
@@ -513,6 +540,10 @@ BuildFv3Hob (
   EFI_HOB_FIRMWARE_VOLUME3  *Hob;
 
   Hob = CreateHob (EFI_HOB_TYPE_FV3, sizeof (EFI_HOB_FIRMWARE_VOLUME3));
+  ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return;
+  }
 
   Hob->BaseAddress          = BaseAddress;
   Hob->Length               = Length;
@@ -546,6 +577,10 @@ BuildCpuHob (
   EFI_HOB_CPU  *Hob;
 
   Hob = CreateHob (EFI_HOB_TYPE_CPU, sizeof (EFI_HOB_CPU));
+  ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return;
+  }
 
   Hob->SizeOfMemorySpace = SizeOfMemorySpace;
   Hob->SizeOfIoSpace     = SizeOfIoSpace;
@@ -583,6 +618,10 @@ BuildStackHob (
     );
 
   Hob = CreateHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, sizeof (EFI_HOB_MEMORY_ALLOCATION_STACK));
+  ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return;
+  }
 
   CopyGuid (&(Hob->AllocDescriptor.Name), &gEfiHobMemoryAllocStackGuid);
   Hob->AllocDescriptor.MemoryBaseAddress = BaseAddress;
@@ -664,6 +703,10 @@ BuildMemoryAllocationHob (
     );
 
   Hob = CreateHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, sizeof (EFI_HOB_MEMORY_ALLOCATION));
+  ASSERT (Hob != NULL);
+  if (Hob == NULL) {
+    return;
+  }
 
   ZeroMem (&(Hob->AllocDescriptor.Name), sizeof (EFI_GUID));
   Hob->AllocDescriptor.MemoryBaseAddress = BaseAddress;
diff --git a/UefiPayloadPkg/UefiPayloadEntry/FitUniversalPayloadEntry.c b/UefiPayloadPkg/UefiPayloadEntry/FitUniversalPayloadEntry.c
index d2e7df4fbe..eb0b325369 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/FitUniversalPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/FitUniversalPayloadEntry.c
@@ -207,10 +207,12 @@ AddNewHob (
   }
 
   NewHob.Header = CreateHob (Hob->Header->HobType, Hob->Header->HobLength);
-
-  if (NewHob.Header != NULL) {
-    CopyMem (NewHob.Header + 1, Hob->Header + 1, Hob->Header->HobLength - sizeof (EFI_HOB_GENERIC_HEADER));
+  ASSERT (NewHob.Header != NULL);
+  if (NewHob.Header == NULL) {
+    return;
   }
+
+  CopyMem (NewHob.Header + 1, Hob->Header + 1, Hob->Header->HobLength - sizeof (EFI_HOB_GENERIC_HEADER));
 }
 
 /**
diff --git a/UefiPayloadPkg/UefiPayloadEntry/UniversalPayloadEntry.c b/UefiPayloadPkg/UefiPayloadEntry/UniversalPayloadEntry.c
index f8939efe70..f37c00fad7 100644
--- a/UefiPayloadPkg/UefiPayloadEntry/UniversalPayloadEntry.c
+++ b/UefiPayloadPkg/UefiPayloadEntry/UniversalPayloadEntry.c
@@ -111,10 +111,12 @@ AddNewHob (
   }
 
   NewHob.Header = CreateHob (Hob->Header->HobType, Hob->Header->HobLength);
-
-  if (NewHob.Header != NULL) {
-    CopyMem (NewHob.Header + 1, Hob->Header + 1, Hob->Header->HobLength - sizeof (EFI_HOB_GENERIC_HEADER));
+  ASSERT (NewHob.Header != NULL);
+  if (NewHob.Header == NULL) {
+    return;
   }
+
+  CopyMem (NewHob.Header + 1, Hob->Header + 1, Hob->Header->HobLength - sizeof (EFI_HOB_GENERIC_HEADER));
 }
 
 /**
-- 
2.39.2.windows.1



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