[edk2-devel] [PATCH V2] UefiCpuPkg/MpInitLib: MicrocodeDetect: Ensure checked range is valid

[Ni, Ray]

> > @@ -170,6 +170,7 @@ MicrocodeDetect (
> >      /// Check overflow and whether TotalSize is aligned with 4 bytes.
> >      ///
> >      if ( ((UINTN)MicrocodeEntryPoint + TotalSize) > MicrocodeEnd ||
> > +         ((UINTN)MicrocodeEntryPoint + TotalSize) < (UINTN)
> > + CpuMpData->MicrocodePatchAddress ||

How about below check?
First comparison hits when the sum of MicrocodeEntryPoint and TotalSize overflows.
Second comparison hits when the sum crosses the boundary of the whole microcode buffer boundary
If (((UINTN) MicrocodeEntryPoint > MAX_UINTN - TotalSize) || ((UINTN)MicrocodeEntryPoint + TotalSize) > MicrocodeEnd)


> >           (TotalSize & 0x3) != 0
> >         ) {
> >        MicrocodeEntryPoint = (CPU_MICROCODE_HEADER *) (((UINTN)
> > MicrocodeEntryPoint) + SIZE_1KB);
> > --
> > 2.21.0.windows.1


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