[PATCH v1 0/2][UDK branches][CVE-2017-5753] Additional Bounds Check Bypass issue in SMI handlers

[PATCH v1 0/2][UDK branches][CVE-2017-5753] Additional Bounds Check Bypass issue in SMI handlers

[Hao Wu]

The series aims to mitigate the Bounds Check Bypass (CVE-2017-5753) issues
within SMI handlers. Moreover, this series focuses on those SMI handlers
that exist on the UDK branches but not on the master branch.

Patch 1/2 will be applied on the below UDK branches:
UDK2017
UDK2015
UDK2014.SP1

Patch 2/2 will be applied on the below UDK branches:
UDK2017
UDK2015

A more detailed explanation of the purpose of the series is under the
'Bounds check bypass mitigation' section of the below link:
https://software.intel.com/security-software-guidance/insights/host-firmware-speculative-execution-side-channel-mitigation

And the document at:
https://software.intel.com/security-software-guidance/api-app/sites/default/files/337879-analyzing-potential-bounds-Check-bypass-vulnerabilities.pdf

Cc: Star Zeng <star.zeng@intel.com>
Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>

Hao Wu (2):
  MdeModulePkg/SmmCorePerfLib: [CVE-2017-5753] Fix bounds check bypass
  SecurityPkg/OpalPWSupportLib: [CVE-2017-5753] Fix bounds check bypass

 MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c  | 16 +++++++++++++++-
 SecurityPkg/Library/OpalPasswordSupportLib/OpalPasswordSupportLib.c |  7 ++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

-- 
2.12.0.windows.1

[PATCH v1 1/2] MdeModulePkg/SmmCorePerfLib: [CVE-2017-5753] Fix bounds check bypass

[Hao Wu]

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1194

Speculative execution is used by processor to avoid having to wait for
data to arrive from memory, or for previous operations to finish, the
processor may speculate as to what will be executed.

If the speculation is incorrect, the speculatively executed instructions
might leave hints such as which memory locations have been brought into
cache. Malicious actors can use the bounds check bypass method (code
gadgets with controlled external inputs) to infer data values that have
been used in speculative operations to reveal secrets which should not
otherwise be accessed.

This commit will focus on the SMI handler(s) registered within the
TBD.

Hence, this commit adds a AsmLfence() after the boundary/range checks of
'CommBuffer' to prevent the speculative execution.

A more detailed explanation of the purpose of commit is under the
'Bounds check bypass mitigation' section of the below link:
https://software.intel.com/security-software-guidance/insights/host-firmware-speculative-execution-side-channel-mitigation

And the document at:
https://software.intel.com/security-software-guidance/api-app/sites/default/files/337879-analyzing-potential-bounds-Check-bypass-vulnerabilities.pdf

Cc: Star Zeng <star.zeng@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
---
 MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c b/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c
index cd1f1a5d5f..63c1eea3a2 100644
--- a/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c
+++ b/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c
@@ -16,7 +16,7 @@
 
  SmmPerformanceHandlerEx(), SmmPerformanceHandler() will receive untrusted input and do basic validation.
 
-Copyright (c) 2011 - 2017, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2011 - 2018, 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
@@ -538,6 +538,13 @@ SmmPerformanceHandlerEx (
          break;
        }
 
+       //
+       // The AsmLfence() call here is to ensure the previous range/content
+       // checks for the CommBuffer have been completed before calling
+       // CopyMem().
+       //
+       AsmLfence ();
+
        GaugeEntryExArray = (GAUGE_DATA_ENTRY_EX *) (mGaugeData + 1);
 
        for (Index = 0; Index < NumberOfEntries; Index++) {
@@ -650,6 +657,13 @@ SmmPerformanceHandler (
          break;
        }
 
+       //
+       // The AsmLfence() call here is to ensure the previous range/content
+       // checks for the CommBuffer have been completed before calling
+       // CopyMem().
+       //
+       AsmLfence ();
+
        GaugeEntryExArray = (GAUGE_DATA_ENTRY_EX *) (mGaugeData + 1);
 
        for (Index = 0; Index < NumberOfEntries; Index++) {
-- 
2.12.0.windows.1

Re: [PATCH v1 1/2] MdeModulePkg/SmmCorePerfLib: [CVE-2017-5753] Fix bounds check bypass

[Zeng, Star]

On 2018/11/16 9:37, Hao Wu wrote:
> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1194
> 
> Speculative execution is used by processor to avoid having to wait for
> data to arrive from memory, or for previous operations to finish, the
> processor may speculate as to what will be executed.
> 
> If the speculation is incorrect, the speculatively executed instructions
> might leave hints such as which memory locations have been brought into
> cache. Malicious actors can use the bounds check bypass method (code
> gadgets with controlled external inputs) to infer data values that have
> been used in speculative operations to reveal secrets which should not
> otherwise be accessed.
> 
> This commit will focus on the SMI handler(s) registered within the
> TBD.

What does the 'TBD' mean here?

Thanks,
Star

> 
> Hence, this commit adds a AsmLfence() after the boundary/range checks of
> 'CommBuffer' to prevent the speculative execution.
> 
> A more detailed explanation of the purpose of commit is under the
> 'Bounds check bypass mitigation' section of the below link:
> https://software.intel.com/security-software-guidance/insights/host-firmware-speculative-execution-side-channel-mitigation
> 
> And the document at:
> https://software.intel.com/security-software-guidance/api-app/sites/default/files/337879-analyzing-potential-bounds-Check-bypass-vulnerabilities.pdf
> 
> Cc: Star Zeng <star.zeng@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Hao Wu <hao.a.wu@intel.com>
> ---
>   MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c | 16 +++++++++++++++-
>   1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c b/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c
> index cd1f1a5d5f..63c1eea3a2 100644
> --- a/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c
> +++ b/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c
> @@ -16,7 +16,7 @@
>   
>    SmmPerformanceHandlerEx(), SmmPerformanceHandler() will receive untrusted input and do basic validation.
>   
> -Copyright (c) 2011 - 2017, Intel Corporation. All rights reserved.<BR>
> +Copyright (c) 2011 - 2018, 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
> @@ -538,6 +538,13 @@ SmmPerformanceHandlerEx (
>            break;
>          }
>   
> +       //
> +       // The AsmLfence() call here is to ensure the previous range/content
> +       // checks for the CommBuffer have been completed before calling
> +       // CopyMem().
> +       //
> +       AsmLfence ();
> +
>          GaugeEntryExArray = (GAUGE_DATA_ENTRY_EX *) (mGaugeData + 1);
>   
>          for (Index = 0; Index < NumberOfEntries; Index++) {
> @@ -650,6 +657,13 @@ SmmPerformanceHandler (
>            break;
>          }
>   
> +       //
> +       // The AsmLfence() call here is to ensure the previous range/content
> +       // checks for the CommBuffer have been completed before calling
> +       // CopyMem().
> +       //
> +       AsmLfence ();
> +
>          GaugeEntryExArray = (GAUGE_DATA_ENTRY_EX *) (mGaugeData + 1);
>   
>          for (Index = 0; Index < NumberOfEntries; Index++) {
> 

Re: [PATCH v1 1/2] MdeModulePkg/SmmCorePerfLib: [CVE-2017-5753] Fix bounds check bypass

[Wu, Hao A]

> -----Original Message-----
> From: Zeng, Star
> Sent: Friday, November 16, 2018 11:14 AM
> To: Wu, Hao A; edk2-devel@lists.01.org
> Cc: Laszlo Ersek; Yao, Jiewen; Zeng, Star
> Subject: Re: [edk2] [PATCH v1 1/2] MdeModulePkg/SmmCorePerfLib: [CVE-
> 2017-5753] Fix bounds check bypass
> 
> On 2018/11/16 9:37, Hao Wu wrote:
> > REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1194
> >
> > Speculative execution is used by processor to avoid having to wait for
> > data to arrive from memory, or for previous operations to finish, the
> > processor may speculate as to what will be executed.
> >
> > If the speculation is incorrect, the speculatively executed instructions
> > might leave hints such as which memory locations have been brought into
> > cache. Malicious actors can use the bounds check bypass method (code
> > gadgets with controlled external inputs) to infer data values that have
> > been used in speculative operations to reveal secrets which should not
> > otherwise be accessed.
> >
> > This commit will focus on the SMI handler(s) registered within the
> > TBD.
> 
> What does the 'TBD' mean here?

Sorry. Patch was generated on the wrong commit, I will send a V2 of the series
to address this.

Best Regards,
Hao Wu

> 
> Thanks,
> Star
> 
> >
> > Hence, this commit adds a AsmLfence() after the boundary/range checks of
> > 'CommBuffer' to prevent the speculative execution.
> >
> > A more detailed explanation of the purpose of commit is under the
> > 'Bounds check bypass mitigation' section of the below link:
> > https://software.intel.com/security-software-guidance/insights/host-
> firmware-speculative-execution-side-channel-mitigation
> >
> > And the document at:
> > https://software.intel.com/security-software-guidance/api-
> app/sites/default/files/337879-analyzing-potential-bounds-Check-bypass-
> vulnerabilities.pdf
> >
> > Cc: Star Zeng <star.zeng@intel.com>
> > Cc: Jiewen Yao <jiewen.yao@intel.com>
> > Cc: Laszlo Ersek <lersek@redhat.com>
> > Contributed-under: TianoCore Contribution Agreement 1.1
> > Signed-off-by: Hao Wu <hao.a.wu@intel.com>
> > ---
> >
> MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib.c
> | 16 +++++++++++++++-
> >   1 file changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git
> a/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib
> .c
> b/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib
> .c
> > index cd1f1a5d5f..63c1eea3a2 100644
> > ---
> a/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib
> .c
> > +++
> b/MdeModulePkg/Library/SmmCorePerformanceLib/SmmCorePerformanceLib
> .c
> > @@ -16,7 +16,7 @@
> >
> >    SmmPerformanceHandlerEx(), SmmPerformanceHandler() will receive
> untrusted input and do basic validation.
> >
> > -Copyright (c) 2011 - 2017, Intel Corporation. All rights reserved.<BR>
> > +Copyright (c) 2011 - 2018, 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
> > @@ -538,6 +538,13 @@ SmmPerformanceHandlerEx (
> >            break;
> >          }
> >
> > +       //
> > +       // The AsmLfence() call here is to ensure the previous range/content
> > +       // checks for the CommBuffer have been completed before calling
> > +       // CopyMem().
> > +       //
> > +       AsmLfence ();
> > +
> >          GaugeEntryExArray = (GAUGE_DATA_ENTRY_EX *) (mGaugeData + 1);
> >
> >          for (Index = 0; Index < NumberOfEntries; Index++) {
> > @@ -650,6 +657,13 @@ SmmPerformanceHandler (
> >            break;
> >          }
> >
> > +       //
> > +       // The AsmLfence() call here is to ensure the previous range/content
> > +       // checks for the CommBuffer have been completed before calling
> > +       // CopyMem().
> > +       //
> > +       AsmLfence ();
> > +
> >          GaugeEntryExArray = (GAUGE_DATA_ENTRY_EX *) (mGaugeData + 1);
> >
> >          for (Index = 0; Index < NumberOfEntries; Index++) {
> >

[PATCH v1 2/2] SecurityPkg/OpalPWSupportLib: [CVE-2017-5753] Fix bounds check bypass

[Hao Wu]

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1194

Speculative execution is used by processor to avoid having to wait for
data to arrive from memory, or for previous operations to finish, the
processor may speculate as to what will be executed.

If the speculation is incorrect, the speculatively executed instructions
might leave hints such as which memory locations have been brought into
cache. Malicious actors can use the bounds check bypass method (code
gadgets with controlled external inputs) to infer data values that have
been used in speculative operations to reveal secrets which should not
otherwise be accessed.

This commit will focus on the SMI handler(s) registered within the
OpalPasswordSupportLib and insert AsmLfence API to mitigate the bounds
check bypass issue.

For SMI handler SmmOpalPasswordHandler():

Under "case SMM_FUNCTION_SET_OPAL_PASSWORD:",
'&DeviceBuffer->OpalDevicePath' can points to a potential cross boundary
access of the 'CommBuffer' (controlled external inputs) during speculative
execution. This cross boundary access pointer is later passed as parameter
'DevicePath' into function OpalSavePasswordToSmm().

Within function OpalSavePasswordToSmm(), 'DevicePathLen' is an access to
the content in 'DevicePath' and can be inferred by code:
"CompareMem (&List->OpalDevicePath, DevicePath, DevicePathLen)". One can
observe which part of the content within either '&List->OpalDevicePath' or
'DevicePath' was brought into cache to possibly reveal the value of
'DevicePathLen'.

Hence, this commit adds a AsmLfence() after the boundary/range checks of
'CommBuffer' to prevent the speculative execution.

A more detailed explanation of the purpose of commit is under the
'Bounds check bypass mitigation' section of the below link:
https://software.intel.com/security-software-guidance/insights/host-firmware-speculative-execution-side-channel-mitigation

And the document at:
https://software.intel.com/security-software-guidance/api-app/sites/default/files/337879-analyzing-potential-bounds-Check-bypass-vulnerabilities.pdf

Cc: Star Zeng <star.zeng@intel.com>
Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
---
 SecurityPkg/Library/OpalPasswordSupportLib/OpalPasswordSupportLib.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/SecurityPkg/Library/OpalPasswordSupportLib/OpalPasswordSupportLib.c b/SecurityPkg/Library/OpalPasswordSupportLib/OpalPasswordSupportLib.c
index e377e9ca79..1c3bfffb86 100644
--- a/SecurityPkg/Library/OpalPasswordSupportLib/OpalPasswordSupportLib.c
+++ b/SecurityPkg/Library/OpalPasswordSupportLib/OpalPasswordSupportLib.c
@@ -1,7 +1,7 @@
 /** @file
   Implementation of Opal password support library.
 
-Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2016 - 2018, 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
@@ -706,6 +706,11 @@ SmmOpalPasswordHandler (
         Status = EFI_INVALID_PARAMETER;
         goto EXIT;
       }
+      //
+      // The AsmLfence() call here is to ensure the above range checks for the
+      // CommBuffer have been completed before calling into OpalSavePasswordToSmm().
+      //
+      AsmLfence ();
 
       Status = OpalSavePasswordToSmm (&DeviceBuffer->OpalDevicePath, DeviceBuffer->Password, DeviceBuffer->PasswordLength);
       break;
-- 
2.12.0.windows.1