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authorBret Barkelew <brbarkel@microsoft.com>2020-11-09 14:45:19 +0800
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2020-11-17 01:03:43 +0000
commite176bafc9d80c17c5480e3d749a6ff1fdb7e7fab (patch)
tree9b524131ca8a03393187b7c72250706c8db7ee28 /MdeModulePkg
parentb6490426e3208de7d6cbd756276a02e4329cd85a (diff)
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MdeModulePkg: Allow VariablePolicy state to delete protected variables
https://bugzilla.tianocore.org/show_bug.cgi?id=2522 TcgMorLockSmm provides special protections for the TCG MOR variables. This will check IsVariablePolicyEnabled() before enforcing them to allow variable deletion when policy engine is disabled. Only allows deletion, not modification. Cc: Jian J Wang <jian.j.wang@intel.com> Cc: Hao A Wu <hao.a.wu@intel.com> Cc: Liming Gao <liming.gao@intel.com> Cc: Bret Barkelew <brbarkel@microsoft.com> Signed-off-by: Bret Barkelew <brbarkel@microsoft.com> Reviewed-by: Dandan Bi <dandan.bi@intel.com> Acked-by: Jian J Wang <jian.j.wang@intel.com>
Diffstat (limited to 'MdeModulePkg')
-rw-r--r--MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c10
-rw-r--r--MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf2
2 files changed, 12 insertions, 0 deletions
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
index 6d80eb6434..085f82035f 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
@@ -5,6 +5,7 @@
This module adds Variable Hook and check MemoryOverwriteRequestControlLock.
Copyright (c) 2016 - 2018, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
@@ -17,6 +18,10 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
#include <Library/BaseMemoryLib.h>
#include "Variable.h"
+#include <Protocol/VariablePolicy.h>
+
+#include <Library/VariablePolicyLib.h>
+
typedef struct {
CHAR16 *VariableName;
EFI_GUID *VendorGuid;
@@ -341,6 +346,11 @@ SetVariableCheckHandlerMor (
return EFI_SUCCESS;
}
+ // Permit deletion when policy is disabled.
+ if (!IsVariablePolicyEnabled() && ((Attributes == 0) || (DataSize == 0))) {
+ return EFI_SUCCESS;
+ }
+
//
// MorLock variable
//
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf
index 6e17f6cdf5..d8f480be27 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableStandaloneMm.inf
@@ -20,6 +20,7 @@
#
# Copyright (c) 2010 - 2019, Intel Corporation. All rights reserved.<BR>
# Copyright (c) 2018, Linaro, Ltd. All rights reserved.<BR>
+# Copyright (c) Microsoft Corporation.
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
##
@@ -74,6 +75,7 @@
StandaloneMmDriverEntryPoint
SynchronizationLib
VarCheckLib
+ VariablePolicyLib
[Protocols]
gEfiSmmFirmwareVolumeBlockProtocolGuid ## CONSUMES