File ovmf-bsc1188371-UefiCpuPkg-CpuMpPei-Add-GDT-migration-support-CVE-20.patch of Package ovmf.37685
From 60b12e69fb1c8c7180fdda92f008248b9ec83db1 Mon Sep 17 00:00:00 2001
From: Michael Kubacki <michael.a.kubacki@intel.com>
Date: Sun, 14 Apr 2019 11:48:07 +0800
Subject: [PATCH 3/9] UefiCpuPkg/CpuMpPei: Add GDT migration support
(CVE-2019-11098)
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1614
Moves the GDT to permanent memory in a memory discovered
callback. This is done to ensure the GDT authenticated in
pre-memory is not fetched from outside a verified location
after the permanent memory transition.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
---
UefiCpuPkg/CpuMpPei/CpuMpPei.c | 37 ++++++++++++++++++++++++++++++++
UefiCpuPkg/CpuMpPei/CpuMpPei.h | 12 +++++++++++
UefiCpuPkg/CpuMpPei/CpuMpPei.inf | 1 +
UefiCpuPkg/CpuMpPei/CpuPaging.c | 12 +++++++++--
4 files changed, 60 insertions(+), 2 deletions(-)
Index: edk2-edk2-stable201911/UefiCpuPkg/CpuMpPei/CpuMpPei.c
===================================================================
--- edk2-edk2-stable201911.orig/UefiCpuPkg/CpuMpPei/CpuMpPei.c
+++ edk2-edk2-stable201911/UefiCpuPkg/CpuMpPei/CpuMpPei.c
@@ -430,6 +430,43 @@ GetGdtr (
}
/**
+ Migrates the Global Descriptor Table (GDT) to permanent memory.
+
+ @retval EFI_SUCCESS The GDT was migrated successfully.
+ @retval EFI_OUT_OF_RESOURCES The GDT could not be migrated due to lack of available memory.
+
+**/
+EFI_STATUS
+MigrateGdt (
+ VOID
+ )
+{
+ EFI_STATUS Status;
+ UINTN GdtBufferSize;
+ IA32_DESCRIPTOR Gdtr;
+ VOID *GdtBuffer;
+
+ AsmReadGdtr ((IA32_DESCRIPTOR *) &Gdtr);
+ GdtBufferSize = sizeof (IA32_SEGMENT_DESCRIPTOR) -1 + Gdtr.Limit + 1;
+
+ Status = PeiServicesAllocatePool (
+ GdtBufferSize,
+ &GdtBuffer
+ );
+ ASSERT (GdtBuffer != NULL);
+ if (EFI_ERROR (Status)) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ GdtBuffer = ALIGN_POINTER (GdtBuffer, sizeof (IA32_SEGMENT_DESCRIPTOR));
+ CopyMem (GdtBuffer, (VOID *) Gdtr.Base, Gdtr.Limit + 1);
+ Gdtr.Base = (UINTN) GdtBuffer;
+ AsmWriteGdtr (&Gdtr);
+
+ return EFI_SUCCESS;
+}
+
+/**
Initializes CPU exceptions handlers for the sake of stack switch requirement.
This function is a wrapper of InitializeCpuExceptionHandlersEx. It's mainly
Index: edk2-edk2-stable201911/UefiCpuPkg/CpuMpPei/CpuMpPei.h
===================================================================
--- edk2-edk2-stable201911.orig/UefiCpuPkg/CpuMpPei/CpuMpPei.h
+++ edk2-edk2-stable201911/UefiCpuPkg/CpuMpPei/CpuMpPei.h
@@ -398,6 +398,18 @@ SecPlatformInformation2 (
);
/**
+ Migrates the Global Descriptor Table (GDT) to permanent memory.
+
+ @retval EFI_SUCCESS The GDT was migrated successfully.
+ @retval EFI_OUT_OF_RESOURCES The GDT could not be migrated due to lack of available memory.
+
+**/
+EFI_STATUS
+MigrateGdt (
+ VOID
+ );
+
+/**
Initializes MP and exceptions handlers.
@param PeiServices The pointer to the PEI Services Table.
Index: edk2-edk2-stable201911/UefiCpuPkg/CpuMpPei/CpuMpPei.inf
===================================================================
--- edk2-edk2-stable201911.orig/UefiCpuPkg/CpuMpPei/CpuMpPei.inf
+++ edk2-edk2-stable201911/UefiCpuPkg/CpuMpPei/CpuMpPei.inf
@@ -63,6 +63,7 @@
gUefiCpuPkgTokenSpaceGuid.PcdCpuStackSwitchExceptionList ## SOMETIMES_CONSUMES
gUefiCpuPkgTokenSpaceGuid.PcdCpuKnownGoodStackSize ## SOMETIMES_CONSUMES
gUefiCpuPkgTokenSpaceGuid.PcdCpuApStackSize ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdMigrateTemporaryRamFirmwareVolumes ## CONSUMES
[Depex]
TRUE
Index: edk2-edk2-stable201911/UefiCpuPkg/CpuMpPei/CpuPaging.c
===================================================================
--- edk2-edk2-stable201911.orig/UefiCpuPkg/CpuMpPei/CpuPaging.c
+++ edk2-edk2-stable201911/UefiCpuPkg/CpuMpPei/CpuPaging.c
@@ -602,8 +602,16 @@ MemoryDiscoveredPpiNotifyCallback (
IN VOID *Ppi
)
{
- EFI_STATUS Status;
- BOOLEAN InitStackGuard;
+ EFI_STATUS Status;
+ BOOLEAN InitStackGuard;
+ BOOLEAN InterruptState;
+
+ if (PcdGetBool (PcdMigrateTemporaryRamFirmwareVolumes)) {
+ InterruptState = SaveAndDisableInterrupts ();
+ Status = MigrateGdt ();
+ ASSERT_EFI_ERROR (Status);
+ SetInterruptState (InterruptState);
+ }
//
// Paging must be setup first. Otherwise the exception TSS setup during MP
