From: "Guomin Jiang" <guomin.jiang@intel.com>
To: devel@edk2.groups.io
Cc: Eric Dong <eric.dong@intel.com>, Ray Ni <ray.ni@intel.com>,
Laszlo Ersek <lersek@redhat.com>,
Rahul Kumar <rahul1.kumar@intel.com>
Subject: [PATCH v4 7/9] UefiCpuPkg/CpuMpPei: Enable paging and set NP flag to avoid TOCTOU (CVE-2019-11098)
Date: Wed, 8 Jul 2020 16:10:57 +0800 [thread overview]
Message-ID: <20200708081059.691-8-guomin.jiang@intel.com> (raw)
In-Reply-To: <20200708081059.691-1-guomin.jiang@intel.com>
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1614
To avoid the TOCTOU, enable paging and set Not Present flag so when
access any code in the flash range, it will trigger #NP exception.
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: Guomin Jiang <guomin.jiang@intel.com>
---
UefiCpuPkg/CpuMpPei/CpuMpPei.inf | 3 +++
UefiCpuPkg/CpuMpPei/CpuPaging.c | 26 ++++++++++++++++++++++++--
2 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.inf b/UefiCpuPkg/CpuMpPei/CpuMpPei.inf
index f4d11b861f77..7e511325d8b8 100644
--- a/UefiCpuPkg/CpuMpPei/CpuMpPei.inf
+++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.inf
@@ -46,6 +46,9 @@ [LibraryClasses]
BaseMemoryLib
CpuLib
+[Guids]
+ gEdkiiMigratedFvInfoGuid ## SOMETIMES_CONSUMES ## HOB
+
[Ppis]
gEfiPeiMpServicesPpiGuid ## PRODUCES
gEfiSecPlatformInformationPpiGuid ## SOMETIMES_CONSUMES
diff --git a/UefiCpuPkg/CpuMpPei/CpuPaging.c b/UefiCpuPkg/CpuMpPei/CpuPaging.c
index 3bf0574b34c6..04a16fb2b620 100644
--- a/UefiCpuPkg/CpuMpPei/CpuPaging.c
+++ b/UefiCpuPkg/CpuMpPei/CpuPaging.c
@@ -12,6 +12,7 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
#include <Library/MemoryAllocationLib.h>
#include <Library/CpuLib.h>
#include <Library/BaseLib.h>
+#include <Guid/MigratedFvInfo.h>
#include "CpuMpPei.h"
@@ -605,6 +606,8 @@ MemoryDiscoveredPpiNotifyCallback (
EFI_STATUS Status;
BOOLEAN InitStackGuard;
BOOLEAN InterruptState;
+ EDKII_MIGRATED_FV_INFO *MigratedFvInfo;
+ EFI_PEI_HOB_POINTERS Hob;
if (PcdGetBool (PcdMigrateTemporaryRamFirmwareVolumes)) {
InterruptState = SaveAndDisableInterrupts ();
@@ -619,9 +622,14 @@ MemoryDiscoveredPpiNotifyCallback (
// the task switch (for the sake of stack switch).
//
InitStackGuard = FALSE;
- if (IsIa32PaeSupported () && PcdGetBool (PcdCpuStackGuard)) {
+ Hob.Raw = NULL;
+ if (IsIa32PaeSupported ()) {
+ Hob.Raw = GetFirstGuidHob (&gEdkiiMigratedFvInfoGuid);
+ InitStackGuard = PcdGetBool (PcdCpuStackGuard);
+ }
+
+ if (InitStackGuard || Hob.Raw != NULL) {
EnablePaging ();
- InitStackGuard = TRUE;
}
Status = InitializeCpuMpWorker ((CONST EFI_PEI_SERVICES **)PeiServices);
@@ -631,6 +639,20 @@ MemoryDiscoveredPpiNotifyCallback (
SetupStackGuardPage ();
}
+ while (Hob.Raw != NULL) {
+ MigratedFvInfo = GET_GUID_HOB_DATA (Hob);
+
+ //
+ // Enable #NP exception, so if the code access after disable NEM, it will generate
+ // to avoid potential vulnerability.
+ //
+ ConvertMemoryPageAttributes (MigratedFvInfo->FvOrgBase, MigratedFvInfo->FvLength, 0);
+
+ Hob.Raw = GET_NEXT_HOB (Hob);
+ Hob.Raw = GetNextGuidHob (&gEdkiiMigratedFvInfoGuid, Hob.Raw);
+ }
+ CpuFlushTlb ();
+
return Status;
}
--
2.25.1.windows.1
next prev parent reply other threads:[~2020-07-08 8:11 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 8:10 [PATCH v4 0/9] Add new feature that evacuate temporary to permanent memory (CVE-2019-11098) Guomin Jiang
2020-07-08 8:10 ` [PATCH v4 1/9] MdeModulePkg: Add new PCD to control the evacuate temporary memory feature (CVE-2019-11098) Guomin Jiang
2020-07-08 17:03 ` [edk2-devel] " Laszlo Ersek
2020-07-08 8:10 ` [PATCH v4 2/9] MdeModulePkg/PeiCore: Enable T-RAM evacuation in PeiCore (CVE-2019-11098) Guomin Jiang
2020-07-08 17:13 ` [edk2-devel] " Laszlo Ersek
2020-07-08 8:10 ` [PATCH v4 3/9] UefiCpuPkg/CpuMpPei: Add GDT and IDT migration support (CVE-2019-11098) Guomin Jiang
2020-07-08 17:23 ` [edk2-devel] " Laszlo Ersek
2020-07-08 8:10 ` [PATCH v4 4/9] UefiCpuPkg/SecMigrationPei: Add initial PEIM (CVE-2019-11098) Guomin Jiang
2020-07-08 17:35 ` [edk2-devel] " Laszlo Ersek
2020-07-08 8:10 ` [PATCH v4 5/9] MdeModulePkg/Core: Create Migrated FV Info Hob for calculating hash (CVE-2019-11098) Guomin Jiang
2020-07-08 17:29 ` [edk2-devel] " Laszlo Ersek
2020-07-08 8:10 ` [PATCH v4 6/9] SecurityPkg/Tcg2Pei: Use " Guomin Jiang
2020-07-08 8:10 ` Guomin Jiang [this message]
2020-07-08 17:54 ` [edk2-devel] [PATCH v4 7/9] UefiCpuPkg/CpuMpPei: Enable paging and set NP flag to avoid TOCTOU (CVE-2019-11098) Laszlo Ersek
2020-07-08 8:10 ` [PATCH v4 8/9] UefiCpuPkg: Correct some typos Guomin Jiang
2020-07-08 18:02 ` [edk2-devel] " Laszlo Ersek
2020-07-08 8:10 ` [PATCH v4 9/9] SecurityPkg/TcgPei: Use Migrated FV Info Hob for calculating hash (CVE-2019-11098) Guomin Jiang
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