File ovmf-bsc1196741-MdeModulePkg-PiSmmCore-SmmEntryPoint-underflow-CVE-2.patch of Package ovmf.28617
From cab1f02565d3b29081dd21afb074f35fdb4e1fd6 Mon Sep 17 00:00:00 2001
From: Miki Demeter <miki.demeter@intel.com>
Date: Thu, 27 Oct 2022 16:20:54 -0700
Subject: [PATCH] =?UTF-8?q?MdeModulePkg/PiSmmCore:=20SmmEntryPoint=20under?=
=?UTF-8?q?flow=C2=A0(CVE-2021-38578)?=
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REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3387
Added use of SafeIntLib to validate values are not causing overflows or
underflows in user controlled values when calculating buffer sizes.
Signed-off-by: Miki Demeter <miki.demeter@intel.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
---
MdeModulePkg/Core/PiSmmCore/PiSmmCore.c | 41 ++++++++++++++++++-----
MdeModulePkg/Core/PiSmmCore/PiSmmCore.h | 1 +
MdeModulePkg/Core/PiSmmCore/PiSmmCore.inf | 1 +
MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c | 31 +++++++++++++----
MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf | 1 +
5 files changed, 60 insertions(+), 15 deletions(-)
Index: edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmCore.c
===================================================================
--- edk2-edk2-stable202008.orig/MdeModulePkg/Core/PiSmmCore/PiSmmCore.c
+++ edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmCore.c
@@ -609,6 +609,7 @@ SmmEndOfS3ResumeHandler (
@param[in] Size2 Size of Buff2
@retval TRUE Buffers overlap in memory.
+ @retval TRUE Math error. Prevents potential math over and underflows.
@retval FALSE Buffer doesn't overlap.
**/
@@ -620,11 +621,24 @@ InternalIsBufferOverlapped (
IN UINTN Size2
)
{
+ UINTN End1;
+ UINTN End2;
+ BOOLEAN IsOverUnderflow1;
+ BOOLEAN IsOverUnderflow2;
+
+ // Check for over or underflow
+ IsOverUnderflow1 = EFI_ERROR (SafeUintnAdd ((UINTN)Buff1, Size1, &End1));
+ IsOverUnderflow2 = EFI_ERROR (SafeUintnAdd ((UINTN)Buff2, Size2, &End2));
+
+ if (IsOverUnderflow1 || IsOverUnderflow2) {
+ return TRUE;
+ }
+
//
// If buff1's end is less than the start of buff2, then it's ok.
// Also, if buff1's start is beyond buff2's end, then it's ok.
//
- if (((Buff1 + Size1) <= Buff2) || (Buff1 >= (Buff2 + Size2))) {
+ if ((End1 <= (UINTN)Buff2) || ((UINTN)Buff1 >= End2)) {
return FALSE;
}
@@ -650,6 +664,7 @@ SmmEntryPoint (
EFI_SMM_COMMUNICATE_HEADER *CommunicateHeader;
BOOLEAN InLegacyBoot;
BOOLEAN IsOverlapped;
+ BOOLEAN IsOverUnderflow;
VOID *CommunicationBuffer;
UINTN BufferSize;
@@ -698,17 +713,25 @@ SmmEntryPoint (
(UINT8 *) gSmmCorePrivate,
sizeof (*gSmmCorePrivate)
);
- if (!SmmIsBufferOutsideSmmValid ((UINTN)CommunicationBuffer, BufferSize) || IsOverlapped) {
+ //
+ // Check for over or underflows
+ //
+ IsOverUnderflow = EFI_ERROR (SafeUintnSub (BufferSize, OFFSET_OF (EFI_SMM_COMMUNICATE_HEADER, Data), &BufferSize));
+
+ if (!SmmIsBufferOutsideSmmValid ((UINTN)CommunicationBuffer, BufferSize) ||
+ IsOverlapped || IsOverUnderflow)
+ {
//
// If CommunicationBuffer is not in valid address scope,
// or there is overlap between gSmmCorePrivate and CommunicationBuffer,
+ // or there is over or underflow,
// return EFI_INVALID_PARAMETER
//
gSmmCorePrivate->CommunicationBuffer = NULL;
gSmmCorePrivate->ReturnStatus = EFI_ACCESS_DENIED;
} else {
CommunicateHeader = (EFI_SMM_COMMUNICATE_HEADER *)CommunicationBuffer;
- BufferSize -= OFFSET_OF (EFI_SMM_COMMUNICATE_HEADER, Data);
+ // BufferSize was updated by the SafeUintnSub() call above.
Status = SmiManage (
&CommunicateHeader->HeaderGuid,
NULL,
Index: edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmCore.h
===================================================================
--- edk2-edk2-stable202008.orig/MdeModulePkg/Core/PiSmmCore/PiSmmCore.h
+++ edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmCore.h
@@ -54,6 +54,7 @@
#include <Library/PerformanceLib.h>
#include <Library/HobLib.h>
#include <Library/SmmMemLib.h>
+#include <Library/SafeIntLib.h>
#include "PiSmmCorePrivateData.h"
#include "HeapGuard.h"
Index: edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmCore.inf
===================================================================
--- edk2-edk2-stable202008.orig/MdeModulePkg/Core/PiSmmCore/PiSmmCore.inf
+++ edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmCore.inf
@@ -60,6 +60,7 @@
PerformanceLib
HobLib
SmmMemLib
+ SafeIntLib
[Protocols]
gEfiDxeSmmReadyToLockProtocolGuid ## UNDEFINED # SmiHandlerRegister
Index: edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c
===================================================================
--- edk2-edk2-stable202008.orig/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c
+++ edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c
@@ -34,8 +34,8 @@
#include <Library/UefiRuntimeLib.h>
#include <Library/PcdLib.h>
#include <Library/ReportStatusCodeLib.h>
-
#include "PiSmmCorePrivateData.h"
+#include <Library/SafeIntLib.h>
#define SMRAM_CAPABILITIES (EFI_MEMORY_WB | EFI_MEMORY_UC)
@@ -1344,6 +1344,7 @@ SmmSplitSmramEntry (
@param[in] ReservedRangeToCompare Pointer to EFI_SMM_RESERVED_SMRAM_REGION to compare.
@retval TRUE There is overlap.
+ @retval TRUE Math error.
@retval FALSE There is no overlap.
**/
Index: edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf
===================================================================
--- edk2-edk2-stable202008.orig/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf
+++ edk2-edk2-stable202008/MdeModulePkg/Core/PiSmmCore/PiSmmIpl.inf
@@ -46,6 +46,7 @@
DxeServicesLib
PcdLib
ReportStatusCodeLib
+ SafeIntLib
[Protocols]
gEfiSmmBase2ProtocolGuid ## PRODUCES
