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author | Star Zeng <star.zeng@intel.com> | 2017-02-28 14:01:47 +0800 |
---|---|---|
committer | Star Zeng <star.zeng@intel.com> | 2018-10-17 11:32:31 +0800 |
commit | 2bfddc064b1cd1f4539350bff1473a9c371865d8 (patch) | |
tree | 62cc89adebeaf9099ba9b52563ee002736aeff76 | |
parent | 1a55083d6a815a02dc0225eb95868ec64c72e8ee (diff) | |
download | edk2-2bfddc064b1cd1f4539350bff1473a9c371865d8.tar.gz |
MdeModulePkg Variable: Fix Timestamp zeroing issue on APPEND_WRITE
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=415
When SetVariable() to a time based auth variable with APPEND_WRITE
attribute, and if the EFI_VARIABLE_AUTHENTICATION_2.TimeStamp in
the input Data is earlier than current value, it will cause timestamp
zeroing.
This issue may bring time based auth variable downgrade problem.
For example:
A vendor released three certs at 2014, 2015, and 2016, and system
integrated the 2016 cert. User can SetVariable() with 2015 cert and
APPEND_WRITE attribute to cause timestamp zeroing first, then
SetVariable() with 2014 cert to downgrade the cert.
This patch fixes this issue.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Chao Zhang <chao.b.zhang@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
(cherry picked from commit b7dc8888f31402f410c53242839271ba3b94b619)
-rw-r--r-- | MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c index 43360ee6cd..da2229ba53 100644 --- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c +++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c @@ -2495,6 +2495,8 @@ UpdateVariable ( if (Variable->CurrPtr != NULL) {
if (VariableCompareTimeStampInternal (&(((AUTHENTICATED_VARIABLE_HEADER *) Variable->CurrPtr)->TimeStamp), TimeStamp)) {
CopyMem (&AuthVariable->TimeStamp, TimeStamp, sizeof (EFI_TIME));
+ } else {
+ CopyMem (&AuthVariable->TimeStamp, &(((AUTHENTICATED_VARIABLE_HEADER *) CacheVariable->CurrPtr)->TimeStamp), sizeof (EFI_TIME));
}
}
}
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