From 7db1458f759c2e22ebb4c66bc61aa5dbae1e5fa1 Mon Sep 17 00:00:00 2001 From: Hao Wu Date: Tue, 6 Mar 2018 19:34:38 +0800 Subject: [PATCH] MdeModulePkg/Core: Fix feature conflict between NX and Stack guard If enabled, NX memory protection feature will mark some types of active memory as NX (non-executable), which includes the first page of the stack. This will overwrite the attributes of the first page of the stack if the stack guard feature is also enabled. The solution is to override the attributes setting to the first page of the stack by adding back the 'EFI_MEMORY_RP' attribute when the stack guard feature is enabled. Cc: Star Zeng Cc: Eric Dong Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Hao Wu Reviewed-by: Jiewen Yao Reviewed-by: Jian J Wang Reviewed-by: Ruiyu Ni --- MdeModulePkg/Core/Dxe/DxeMain.inf | 4 +- MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c | 62 +++++++++++++++++-- 2 files changed, 61 insertions(+), 5 deletions(-) diff --git a/MdeModulePkg/Core/Dxe/DxeMain.inf b/MdeModulePkg/Core/Dxe/DxeMain.inf index 7334780326..d2e7360ed4 100644 --- a/MdeModulePkg/Core/Dxe/DxeMain.inf +++ b/MdeModulePkg/Core/Dxe/DxeMain.inf @@ -3,7 +3,7 @@ # # It provides an implementation of DXE Core that is compliant with DXE CIS. # -# Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.
+# Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
# This program and the accompanying materials # are licensed and made available under the terms and conditions of the BSD License # which accompanies this distribution. The full text of the license may be found at @@ -130,6 +130,7 @@ gEfiPropertiesTableGuid ## SOMETIMES_PRODUCES ## SystemTable gEfiMemoryAttributesTableGuid ## SOMETIMES_PRODUCES ## SystemTable gEfiEndOfDxeEventGroupGuid ## SOMETIMES_CONSUMES ## Event + gEfiHobMemoryAllocStackGuid ## SOMETIMES_CONSUMES ## SystemTable [Ppis] gEfiVectorHandoffInfoPpiGuid ## UNDEFINED # HOB @@ -198,6 +199,7 @@ gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPageType ## CONSUMES gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPoolType ## CONSUMES gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask ## CONSUMES + gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard ## CONSUMES # [Hob] # RESOURCE_DESCRIPTOR ## CONSUMES diff --git a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c index a2ea445eef..407aece807 100644 --- a/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c +++ b/MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c @@ -801,6 +801,9 @@ InitializeDxeNxMemoryProtectionPolicy ( UINT64 Attributes; LIST_ENTRY *Link; EFI_GCD_MAP_ENTRY *Entry; + EFI_PEI_HOB_POINTERS Hob; + EFI_HOB_MEMORY_ALLOCATION *MemoryHob; + EFI_PHYSICAL_ADDRESS StackBase; // // Get the EFI memory map. @@ -832,6 +835,40 @@ InitializeDxeNxMemoryProtectionPolicy ( } while (Status == EFI_BUFFER_TOO_SMALL); ASSERT_EFI_ERROR (Status); + StackBase = 0; + if (PcdGetBool (PcdCpuStackGuard)) { + // + // Get the base of stack from Hob. + // + Hob.Raw = GetHobList (); + while ((Hob.Raw = GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, Hob.Raw)) != NULL) { + MemoryHob = Hob.MemoryAllocation; + if (CompareGuid(&gEfiHobMemoryAllocStackGuid, &MemoryHob->AllocDescriptor.Name)) { + DEBUG (( + DEBUG_INFO, + "%a: StackBase = 0x%016lx StackSize = 0x%016lx\n", + __FUNCTION__, + MemoryHob->AllocDescriptor.MemoryBaseAddress, + MemoryHob->AllocDescriptor.MemoryLength + )); + + StackBase = MemoryHob->AllocDescriptor.MemoryBaseAddress; + // + // Ensure the base of the stack is page-size aligned. + // + ASSERT ((StackBase & EFI_PAGE_MASK) == 0); + break; + } + Hob.Raw = GET_NEXT_HOB (Hob); + } + + // + // Ensure the base of stack can be found from Hob when stack guard is + // enabled. + // + ASSERT (StackBase != 0); + } + DEBUG (( DEBUG_INFO, "%a: applying strict permissions to active memory regions\n", @@ -851,19 +888,36 @@ InitializeDxeNxMemoryProtectionPolicy ( LShiftU64 (MemoryMapEntry->NumberOfPages, EFI_PAGE_SHIFT), Attributes); + // + // Add EFI_MEMORY_RP attribute for page 0 if NULL pointer detection is + // enabled. + // if (MemoryMapEntry->PhysicalStart == 0 && PcdGet8 (PcdNullPointerDetectionPropertyMask) != 0) { ASSERT (MemoryMapEntry->NumberOfPages > 0); - // - // Add EFI_MEMORY_RP attribute for page 0 if NULL pointer detection is - // enabled. - // SetUefiImageMemoryAttributes ( 0, EFI_PAGES_TO_SIZE (1), EFI_MEMORY_RP | Attributes); } + + // + // Add EFI_MEMORY_RP attribute for the first page of the stack if stack + // guard is enabled. + // + if (StackBase != 0 && + (StackBase >= MemoryMapEntry->PhysicalStart && + StackBase < MemoryMapEntry->PhysicalStart + + LShiftU64 (MemoryMapEntry->NumberOfPages, EFI_PAGE_SHIFT)) && + PcdGetBool (PcdCpuStackGuard)) { + + SetUefiImageMemoryAttributes ( + StackBase, + EFI_PAGES_TO_SIZE (1), + EFI_MEMORY_RP | Attributes); + } + } MemoryMapEntry = NEXT_MEMORY_DESCRIPTOR (MemoryMapEntry, DescriptorSize); } -- 2.39.2