Reviewed-by: Liming Gao <liming....@intel.com>
>-----Original Message----- >From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of Star >Zeng >Sent: Monday, June 19, 2017 6:24 PM >To: edk2-devel@lists.01.org >Cc: Yao, Jiewen <jiewen....@intel.com>; Zeng, Star <star.z...@intel.com>; >Gao, Liming <liming....@intel.com> >Subject: [edk2] [PATCH] MdeModulePkg: Fix use-after-free error in >InstallConfigurationTable() > >From: "Shi, Steven" <steven....@intel.com> > >When installing configuration table and the original >gDxeCoreST->ConfigurationTable[] buffer happen to be not big enough to >add a new table, the CoreInstallConfigurationTable() enter the branch >of line 113 in InstallConfigurationTable.c to free the old >gDxeCoreST->ConfigurationTable[] buffer and allocate a new bigger one. >The problem happens at line 139 CoreFreePool(), which is to free the >old gDxeCoreST->ConfigurationTable[] buffer. The CoreFreePool()'s >behavior is to free the buffer firstly, then call the >InstallMemoryAttributesTableOnMemoryAllocation (PoolType) to update >the EfiRuntimeServices type memory info, the >CoreInstallConfigurationTable() will be re-entered by CoreFreePool() >in its calling stack, then use-after-free read error will happen at >line 59 of InstallConfigurationTable.c and use-after-free write error >will happen at line 151 and 152 of InstallConfigurationTable.c. > >The patch is to update System table to the new table pointer before >calling CoreFreePool() to free the old table. > >The case above is in DxeCore, but not in PiSmmCore. >The change in PiSmmCore is to be consistent with DxeCore. > >Cc: Jiewen Yao <jiewen....@intel.com> >Cc: Liming Gao <liming....@intel.com> >Contributed-under: TianoCore Contribution Agreement 1.0 >Signed-off-by: Steven Shi <steven....@intel.com> >Signed-off-by: Star Zeng <star.z...@intel.com> >--- > .../Core/Dxe/Misc/InstallConfigurationTable.c | 34 ++++++++++++++++---- >-- > .../Core/PiSmmCore/InstallConfigurationTable.c | 34 ++++++++++++++++-- >---- > 2 files changed, 50 insertions(+), 18 deletions(-) > mode change 100644 => 100755 >MdeModulePkg/Core/Dxe/Misc/InstallConfigurationTable.c > >diff --git a/MdeModulePkg/Core/Dxe/Misc/InstallConfigurationTable.c >b/MdeModulePkg/Core/Dxe/Misc/InstallConfigurationTable.c >old mode 100644 >new mode 100755 >index e4735db7ba45..dcdeb7f45803 >--- a/MdeModulePkg/Core/Dxe/Misc/InstallConfigurationTable.c >+++ b/MdeModulePkg/Core/Dxe/Misc/InstallConfigurationTable.c >@@ -1,7 +1,7 @@ > /** @file > UEFI Miscellaneous boot Services InstallConfigurationTable service > >-Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR> >+Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR> > 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 >@@ -42,6 +42,7 @@ CoreInstallConfigurationTable ( > { > UINTN Index; > EFI_CONFIGURATION_TABLE *EfiConfigurationTable; >+ EFI_CONFIGURATION_TABLE *OldTable; > > // > // If Guid is NULL, then this operation cannot be performed >@@ -68,7 +69,7 @@ CoreInstallConfigurationTable ( > if (Table != NULL) { > // > // If Table is not NULL, then this is a modify operation. >- // Modify the table enty and return. >+ // Modify the table entry and return. > // > gDxeCoreST->ConfigurationTable[Index].VendorTable = Table; > >@@ -134,15 +135,30 @@ CoreInstallConfigurationTable ( > ); > > // >- // Free Old Table >+ // Record the old table pointer. > // >- CoreFreePool (gDxeCoreST->ConfigurationTable); >- } >+ OldTable = gDxeCoreST->ConfigurationTable; > >- // >- // Update System Table >- // >- gDxeCoreST->ConfigurationTable = EfiConfigurationTable; >+ // >+ // As the CoreInstallConfigurationTable() may be re-entered by >CoreFreePool() >+ // in its calling stack, updating System table to the new table >pointer >must >+ // be done before calling CoreFreePool() to free the old table. >+ // It can make sure the gDxeCoreST->ConfigurationTable point to the >new table >+ // and avoid the errors of use-after-free to the old table by the >reenter >of >+ // CoreInstallConfigurationTable() in CoreFreePool()'s calling stack. >+ // >+ gDxeCoreST->ConfigurationTable = EfiConfigurationTable; >+ >+ // >+ // Free the old table after updating System Table to the new table >pointer. >+ // >+ CoreFreePool (OldTable); >+ } else { >+ // >+ // Update System Table >+ // >+ gDxeCoreST->ConfigurationTable = EfiConfigurationTable; >+ } > } > > // >diff --git a/MdeModulePkg/Core/PiSmmCore/InstallConfigurationTable.c >b/MdeModulePkg/Core/PiSmmCore/InstallConfigurationTable.c >index b2f6769c109f..2b6eef9a0e3e 100644 >--- a/MdeModulePkg/Core/PiSmmCore/InstallConfigurationTable.c >+++ b/MdeModulePkg/Core/PiSmmCore/InstallConfigurationTable.c >@@ -1,7 +1,7 @@ > /** @file > System Management System Table Services SmmInstallConfigurationTable >service > >- Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR> >+ Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR> > 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 >@@ -46,6 +46,7 @@ SmmInstallConfigurationTable ( > { > UINTN Index; > EFI_CONFIGURATION_TABLE *ConfigurationTable; >+ EFI_CONFIGURATION_TABLE *OldTable; > > // > // If Guid is NULL, then this operation cannot be performed >@@ -72,7 +73,7 @@ SmmInstallConfigurationTable ( > if (Table != NULL) { > // > // If Table is not NULL, then this is a modify operation. >- // Modify the table enty and return. >+ // Modify the table entry and return. > // > ConfigurationTable[Index].VendorTable = Table; > return EFI_SUCCESS; >@@ -130,15 +131,30 @@ SmmInstallConfigurationTable ( > ); > > // >- // Free Old Table >+ // Record the old table pointer. > // >- FreePool (gSmmCoreSmst.SmmConfigurationTable); >- } >+ OldTable = gSmmCoreSmst.SmmConfigurationTable; > >- // >- // Update System Table >- // >- gSmmCoreSmst.SmmConfigurationTable = ConfigurationTable; >+ // >+ // As the SmmInstallConfigurationTable() may be re-entered by >FreePool() in >+ // its calling stack, updating System table to the new table pointer >must >+ // be done before calling FreePool() to free the old table. >+ // It can make sure the gSmmCoreSmst->SmmConfigurationTable point >to the new >+ // table and avoid the errors of use-after-free to the old table by >the >+ // reenter of SmmInstallConfigurationTable() in FreePool()'s calling >stack. >+ // >+ gSmmCoreSmst.SmmConfigurationTable = ConfigurationTable; >+ >+ // >+ // Free the old table after updating System Table to the new table >pointer. >+ // >+ FreePool (OldTable); >+ } else { >+ // >+ // Update System Table >+ // >+ gSmmCoreSmst.SmmConfigurationTable = ConfigurationTable; >+ } > } > > // >-- >2.7.0.windows.1 > >_______________________________________________ >edk2-devel mailing list >edk2-devel@lists.01.org >https://lists.01.org/mailman/listinfo/edk2-devel _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel
