From 155eceaf831492dcd77172833350072e4156e1c9 Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Tue, 5 Mar 2024 16:38:49 -0500
Subject: [PATCH 2/2] StandaloneMmPkg/Hob: Integer Overflow in CreateHob()

RH-Author: Jon Maloy <jmaloy@redhat.com>
RH-MergeRequest: 66: EmbeddedPkg/Hob: Integer Overflow in CreateHob()
RH-Jira: RHEL-21158
RH-Acked-by: Oliver Steffen <osteffen@redhat.com>
RH-Acked-by: Gerd Hoffmann <None>
RH-Commit: [2/2] be7ee11a65a56faec07c249a35940cf9b95b9ec1

JIRA: https://issues.redhat.com/browse/RHEL-21158
CVE: CVE-2022-36765
Upstream: Merged

commit 9a75b030cf27d2530444e9a2f9f11867f79bf679
Author: Gua Guo <gua.guo@intel.com>
Date:   Thu Jan 11 13:03:26 2024 +0800

    StandaloneMmPkg/Hob: Integer Overflow in CreateHob()

    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>
    Reviewed-by: Ard Biesheuvel <ardb+tianocore@kernel.org>
    Cc: Sami Mujawar <sami.mujawar@arm.com>
    Reviewed-by: Ray Ni <ray.ni@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>

 Signed-off-by: Jon Maloy <jmaloy@redhat.com>
---
 .../Arm/StandaloneMmCoreHobLib.c              | 37 ++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/StandaloneMmPkg/Library/StandaloneMmCoreHobLib/Arm/StandaloneMmCoreHobLib.c b/StandaloneMmPkg/Library/StandaloneMmCoreHobLib/Arm/StandaloneMmCoreHobLib.c
index 0ec2d4ad6f..3b13249e33 100644
--- a/StandaloneMmPkg/Library/StandaloneMmCoreHobLib/Arm/StandaloneMmCoreHobLib.c
+++ b/StandaloneMmPkg/Library/StandaloneMmCoreHobLib/Arm/StandaloneMmCoreHobLib.c
@@ -34,6 +34,13 @@ 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;
@@ -87,6 +94,10 @@ BuildModuleHob (
           ((ModuleLength & (EFI_PAGE_SIZE - 1)) == 0));
 
   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;
@@ -127,6 +138,9 @@ 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;
@@ -164,7 +178,12 @@ BuildGuidHob (
   //
   ASSERT (DataLength <= (0xffff - sizeof (EFI_HOB_GUID_TYPE)));
 
-  Hob = CreateHob (EFI_HOB_TYPE_GUID_EXTENSION, (UINT16) (sizeof (EFI_HOB_GUID_TYPE) + DataLength));
+  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;
 }
@@ -225,6 +244,10 @@ 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;
@@ -255,6 +278,10 @@ 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;
@@ -283,6 +310,10 @@ 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;
@@ -318,6 +349,10 @@ BuildMemoryAllocationHob (
           ((Length & (EFI_PAGE_SIZE - 1)) == 0));
 
   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;
-- 
2.39.3