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| author | Hao Wu <hao.a.wu@intel.com> | 2018-08-16 10:38:10 +0800 |
|---|---|---|
| committer | Hao Wu <hao.a.wu@intel.com> | 2018-11-16 09:00:05 +0800 |
| commit | 94c43d6fa64481e2f9ee1d96949349a0b9254352 (patch) | |
| tree | 1b8eb735bfd5d7611d60b02c40c14b4b6c7d7f8d /UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmiException.nasm | |
| parent | ad4bebe21f684d404949fd60f77d461934f70393 (diff) | |
| download | edk2-94c43d6fa64481e2f9ee1d96949349a0b9254352.tar.gz | |
UefiCpuPkg/SmmCpuFeaturesLib: [CVE-2017-5715] Stuff RSB before RSM
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1093
Return Stack Buffer (RSB) is used to predict the target of RET
instructions. When the RSB underflows, some processors may fall back to
using branch predictors. This might impact software using the retpoline
mitigation strategy on those processors.
This commit will add RSB stuffing logic before returning from SMM (the RSM
instruction) to avoid interfering with non-SMM usage of the retpoline
technique.
After the stuffing, RSB entries will contain a trap like:
@SpecTrap:
pause
lfence
jmp @SpecTrap
A more detailed explanation of the purpose of commit is under the
'Branch target injection mitigation' section of the below link:
https://software.intel.com/security-software-guidance/insights/host-firmware-speculative-execution-side-channel-mitigation
Please note that this commit requires further actions (BZ 1091) to remove
the duplicated 'StuffRsb.inc' files and merge them into one under a
UefiCpuPkg package-level directory (such as UefiCpuPkg/Include/).
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1091
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Eric Dong <eric.dong@intel.com>
(cherry picked from commit 0df5056012e64fdf14cab0cd94e3b8630a3a88ba)
Diffstat (limited to 'UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmiException.nasm')
| -rw-r--r-- | UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmiException.nasm | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmiException.nasm b/UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmiException.nasm index b0ab87b0d4..3e5295986b 100644 --- a/UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmiException.nasm +++ b/UefiCpuPkg/Library/SmmCpuFeaturesLib/X64/SmiException.nasm @@ -18,6 +18,8 @@ ;
;-------------------------------------------------------------------------------
+%include "StuffRsb.inc"
+
global ASM_PFX(gcStmPsd)
extern ASM_PFX(SmmStmExceptionHandler)
@@ -131,7 +133,8 @@ ASM_PFX(OnStmSetup): wrmsr
.11:
- rsm
+ StuffRsb64
+ rsm
global ASM_PFX(OnStmTeardown)
ASM_PFX(OnStmTeardown):
@@ -175,4 +178,5 @@ ASM_PFX(OnStmTeardown): wrmsr
.12:
- rsm
+ StuffRsb64
+ rsm
|