[edk2-devel] [PATCH] MdeModulePkg/DxeCore: Consistent DebugImageInfoTable updates
Wu, Hao A
hao.a.wu at intel.com
Mon Aug 9 06:10:59 UTC 2021
Sorry Marvin Häuser,
Could you help to confirm that below 9 MdeModulePkg related patches are either:
* All independent patches
* Belong to a patch series that includes all these 9 MdeModulePkg related commits
* Belong to several independent patch series
MdePkg/Base.h: Introduce various alignment-related macros
MdeModulePkg/CoreDxe: Mandatory LoadedImage for DebugImageInfoTable
MdeModulePkg/DxeCore: Fix DebugImageInfoTable size report
MdeModulePkg/DxeCore: Use the correct source for fixed load address
MdeModulePkg/PiSmmCore: Drop deprecated image profiling commands
MdeModulePkg/CoreDxe: Drop caller-allocated image buffers
MdeModulePkg/DxeCore: Drop unnecessary pointer indirection
MdeModulePkg/PiSmmIpl: Correct fixed load address bounds check
MdeModulePkg/DxeCore: Consistent DebugImageInfoTable updates
Best Regards,
Hao Wu
> -----Original Message-----
> From: Marvin Häuser <mhaeuser at posteo.de>
> Sent: Monday, August 9, 2021 3:40 AM
> To: devel at edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang at intel.com>; Wu, Hao A <hao.a.wu at intel.com>;
> Bi, Dandan <dandan.bi at intel.com>; Liming Gao
> <gaoliming at byosoft.com.cn>; Vitaly Cheptsov <vit9696 at protonmail.com>
> Subject: [PATCH] MdeModulePkg/DxeCore: Consistent
> DebugImageInfoTable updates
>
> In theory, modifications to the DebugImageInfoTable may cause exceptions.
> If the exception handler parses the table, this can lead to subsequent
> exceptions if the table state is inconsistent.
>
> Ensure the DebugImageInfoTable remains consistent during modifications.
> This includes:
> 1) Free the old table only only after the new table has been published.
> Mitigates use-after-free of the old table.
> 2) Do not insert an image entry till it is fully initialised. Entries may be inserted
> in the live range if an entry was deleted previously.
> Mitigaes the usage of inconsistent entries.
> 3) Free the old image entry only after the table has been updated with the
> NULL value. Mitigates use-after-free of the old entry.
> 4) Set the MODIFIED state before performing any modifications.
>
> Cc: Jian J Wang <jian.j.wang at intel.com>
> Cc: Hao A Wu <hao.a.wu at intel.com>
> Cc: Dandan Bi <dandan.bi at intel.com>
> Cc: Liming Gao <gaoliming at byosoft.com.cn>
> Cc: Vitaly Cheptsov <vit9696 at protonmail.com>
> Signed-off-by: Marvin Häuser <mhaeuser at posteo.de>
> ---
> MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c | 60 +++++++++++------
> ---
> 1 file changed, 34 insertions(+), 26 deletions(-)
>
> diff --git a/MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c
> b/MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c
> index a75d4158280b..7bd970115111 100644
> --- a/MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c
> +++ b/MdeModulePkg/Core/Dxe/Misc/DebugImageInfo.c
> @@ -165,10 +165,11 @@ CoreNewDebugImageInfoEntry (
> IN EFI_HANDLE ImageHandle ) {- EFI_DEBUG_IMAGE_INFO
> *Table;- EFI_DEBUG_IMAGE_INFO *NewTable;- UINTN Index;-
> UINTN TableSize;+ EFI_DEBUG_IMAGE_INFO *Table;+
> EFI_DEBUG_IMAGE_INFO *NewTable;+ UINTN Index;+
> UINTN TableSize;+ EFI_DEBUG_IMAGE_INFO_NORMAL
> *NormalImage; // // Set the flag indicating that we're in the process of
> updating the table.@@ -203,14 +204,6 @@ CoreNewDebugImageInfoEntry (
> // Copy the old table into the new one // CopyMem (NewTable, Table,
> TableSize);- //- // Free the old table- //- CoreFreePool (Table);- //-
> // Update the table header- //- Table = NewTable;
> mDebugInfoTableHeader.EfiDebugImageInfoTable = NewTable; // //
> Enlarge the max table entries and set the first empty entry index to@@ -
> 218,24 +211,34 @@ CoreNewDebugImageInfoEntry (
> // Index = mMaxTableEntries; mMaxTableEntries +=
> EFI_PAGE_SIZE / EFI_DEBUG_TABLE_ENTRY_SIZE;+ //+ // Free the old
> table+ //+ CoreFreePool (Table);+ //+ // Update the table header+
> //+ Table = NewTable; } // // Allocate data for new entry //-
> Table[Index].NormalImage = AllocateZeroPool (sizeof
> (EFI_DEBUG_IMAGE_INFO_NORMAL));- if (Table[Index].NormalImage !=
> NULL) {+ NormalImage = AllocateZeroPool (sizeof
> (EFI_DEBUG_IMAGE_INFO_NORMAL));+ if (NormalImage != NULL) { //
> // Update the entry //- Table[Index].NormalImage->ImageInfoType
> = (UINT32) ImageInfoType;- Table[Index].NormalImage-
> >LoadedImageProtocolInstance = LoadedImage;-
> Table[Index].NormalImage->ImageHandle = ImageHandle;+
> NormalImage->ImageInfoType = (UINT32) ImageInfoType;+
> NormalImage->LoadedImageProtocolInstance = LoadedImage;+
> NormalImage->ImageHandle = ImageHandle; //- // Increase the
> number of EFI_DEBUG_IMAGE_INFO elements and set the
> mDebugInfoTable in modified status.+ // Set the mDebugInfoTable in
> modified status, insert the entry, and+ // increase the number of
> EFI_DEBUG_IMAGE_INFO elements. //-
> mDebugInfoTableHeader.TableSize++;
> mDebugInfoTableHeader.UpdateStatus |=
> EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;+ Table[Index].NormalImage
> = NormalImage;+ mDebugInfoTableHeader.TableSize++; }
> mDebugInfoTableHeader.UpdateStatus &=
> ~EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS; }@@ -253,8 +256,9
> @@ CoreRemoveDebugImageInfoEntry (
> EFI_HANDLE ImageHandle ) {- EFI_DEBUG_IMAGE_INFO *Table;- UINTN
> Index;+ EFI_DEBUG_IMAGE_INFO *Table;+ UINTN Index;+
> EFI_DEBUG_IMAGE_INFO_NORMAL *NormalImage;
> mDebugInfoTableHeader.UpdateStatus |=
> EFI_DEBUG_IMAGE_INFO_UPDATE_IN_PROGRESS; @@ -263,16 +267,20
> @@ CoreRemoveDebugImageInfoEntry (
> for (Index = 0; Index < mMaxTableEntries; Index++) { if
> (Table[Index].NormalImage != NULL && Table[Index].NormalImage-
> >ImageHandle == ImageHandle) { //- // Found a match. Free up the
> record, then NULL the pointer to indicate the slot- // is free.+ // Found a
> match. Set the mDebugInfoTable in modified status and NULL the+ //
> pointer to indicate the slot is free and. //- CoreFreePool
> (Table[Index].NormalImage);+ NormalImage =
> Table[Index].NormalImage;+ mDebugInfoTableHeader.UpdateStatus |=
> EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED; Table[Index].NormalImage
> = NULL; //- // Decrease the number of EFI_DEBUG_IMAGE_INFO
> elements and set the mDebugInfoTable in modified status.+ // Decrease
> the number of EFI_DEBUG_IMAGE_INFO elements. //
> mDebugInfoTableHeader.TableSize--;-
> mDebugInfoTableHeader.UpdateStatus |=
> EFI_DEBUG_IMAGE_INFO_TABLE_MODIFIED;+ //+ // Free up the
> record.+ //+ CoreFreePool (NormalImage); break; } }--
> 2.31.1
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