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| author | Michael Kubacki <michael.a.kubacki@intel.com> | 2019-04-14 11:48:07 +0800 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2020-07-28 01:43:16 +0000 |
| commit | 60b12e69fb1c8c7180fdda92f008248b9ec83db1 (patch) | |
| tree | cf47f09b41ae3c445366f1522ee0ccc27dc10bc5 /UefiCpuPkg/CpuMpPei/CpuMpPei.c | |
| parent | 9bedaec05b7b8ba9aee248361bb61a85a26726cb (diff) | |
| download | edk2-60b12e69fb1c8c7180fdda92f008248b9ec83db1.tar.gz edk2-60b12e69fb1c8c7180fdda92f008248b9ec83db1.tar.bz2 edk2-60b12e69fb1c8c7180fdda92f008248b9ec83db1.zip | |
UefiCpuPkg/CpuMpPei: Add GDT migration support (CVE-2019-11098)
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1614
Moves the GDT to permanent memory in a memory discovered
callback. This is done to ensure the GDT authenticated in
pre-memory is not fetched from outside a verified location
after the permanent memory transition.
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Signed-off-by: Michael Kubacki <michael.a.kubacki@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
Diffstat (limited to 'UefiCpuPkg/CpuMpPei/CpuMpPei.c')
| -rw-r--r-- | UefiCpuPkg/CpuMpPei/CpuMpPei.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.c b/UefiCpuPkg/CpuMpPei/CpuMpPei.c index 07ccbe7c6a..d07540cf74 100644 --- a/UefiCpuPkg/CpuMpPei/CpuMpPei.c +++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.c @@ -430,6 +430,43 @@ GetGdtr ( }
/**
+ Migrates the Global Descriptor Table (GDT) to permanent memory.
+
+ @retval EFI_SUCCESS The GDT was migrated successfully.
+ @retval EFI_OUT_OF_RESOURCES The GDT could not be migrated due to lack of available memory.
+
+**/
+EFI_STATUS
+MigrateGdt (
+ VOID
+ )
+{
+ EFI_STATUS Status;
+ UINTN GdtBufferSize;
+ IA32_DESCRIPTOR Gdtr;
+ VOID *GdtBuffer;
+
+ AsmReadGdtr ((IA32_DESCRIPTOR *) &Gdtr);
+ GdtBufferSize = sizeof (IA32_SEGMENT_DESCRIPTOR) -1 + Gdtr.Limit + 1;
+
+ Status = PeiServicesAllocatePool (
+ GdtBufferSize,
+ &GdtBuffer
+ );
+ ASSERT (GdtBuffer != NULL);
+ if (EFI_ERROR (Status)) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ GdtBuffer = ALIGN_POINTER (GdtBuffer, sizeof (IA32_SEGMENT_DESCRIPTOR));
+ CopyMem (GdtBuffer, (VOID *) Gdtr.Base, Gdtr.Limit + 1);
+ Gdtr.Base = (UINTN) GdtBuffer;
+ AsmWriteGdtr (&Gdtr);
+
+ return EFI_SUCCESS;
+}
+
+/**
Initializes CPU exceptions handlers for the sake of stack switch requirement.
This function is a wrapper of InitializeCpuExceptionHandlersEx. It's mainly
|