From 0ef57f5f435ee1909d14da24cd1c3edc91fef405 Mon Sep 17 00:00:00 2001
From: Jon Maloy <jmaloy@redhat.com>
Date: Sat, 6 Apr 2024 11:00:29 -0400
Subject: [PATCH 2/2] StandaloneMmPkg/Hob: Integer Overflow in CreateHob()

RH-Author: Jon Maloy <jmaloy@redhat.com>
RH-MergeRequest: 69: EmbeddedPkg/Hob: Integer Overflow in CreateHob()
RH-Jira: RHEL-30156
RH-Acked-by: Oliver Steffen <osteffen@redhat.com>
RH-Acked-by: Gerd Hoffmann <None>
RH-Commit: [2/2] 3c3454688975f62041dd8d3393f0bba5ec3b71f1

JIRA: https://issues.redhat.com/browse/RHEL-30156
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              | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/StandaloneMmPkg/Library/StandaloneMmCoreHobLib/Arm/StandaloneMmCoreHobLib.c b/StandaloneMmPkg/Library/StandaloneMmCoreHobLib/Arm/StandaloneMmCoreHobLib.c
index 1550e1babc..59473e28fe 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;
@@ -89,6 +96,10 @@ 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;
@@ -129,6 +140,9 @@ 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;
@@ -167,6 +181,11 @@ 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;
 }
@@ -226,6 +245,10 @@ 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;
@@ -282,6 +309,10 @@ 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;
@@ -319,6 +350,10 @@ 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;
-- 
2.39.3