On Thu, May 18, 2023 at 4:16 PM Ranbir Singh <rsi...@ventanamicro.com> wrote: > > FspData->PerfIdx is getting increased for every call unconditionally > in the function SetFspMeasurePoint and hence memory access can happen > for out of bound FspData->PerfData[] array entries also. > > Example - > FspData->PerfData is an array of 32 UINT64 entries. Assume a call > is made to SetFspMeasurePoint function when the FspData->PerfIdx > last value is 31. It gets incremented to 32 at line 400. > Any subsequent call to SetFspMeasurePoint functions leads to > FspData->PerfData[32] getting accessed which is out of the PerfData > array as well as the FSP_GLOBAL_DATA structure boundary. > > Hence keep array access and index increment inside if block only and > return invalid performance timestamp when PerfIdx is invalid. > > Cc: Chasel Chiu <chasel.c...@intel.com> > Cc: Nate DeSimone <nathaniel.l.desim...@intel.com> > Cc: Star Zeng <star.z...@intel.com> > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4200 > Signed-off-by: Ranbir Singh <ranbir.sin...@dell.com> > Signed-off-by: Ranbir Singh <rsi...@ventanamicro.com> > --- > IntelFsp2Pkg/Library/BaseFspCommonLib/FspCommonLib.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/IntelFsp2Pkg/Library/BaseFspCommonLib/FspCommonLib.c > b/IntelFsp2Pkg/Library/BaseFspCommonLib/FspCommonLib.c > index a22b0e7825ad..cda2a7b2478e 100644 > --- a/IntelFsp2Pkg/Library/BaseFspCommonLib/FspCommonLib.c > +++ b/IntelFsp2Pkg/Library/BaseFspCommonLib/FspCommonLib.c > @@ -377,7 +377,8 @@ GetFspSiliconInitUpdDataPointer ( > > @param[in] Id Measurement point ID. > > - @return performance timestamp. > + @return performance timestamp if current PerfIdx is valid, > + else return 0 as invalid performance timestamp > **/ > UINT64 > EFIAPI > @@ -395,9 +396,10 @@ SetFspMeasurePoint ( > if (FspData->PerfIdx < sizeof (FspData->PerfData) / sizeof > (FspData->PerfData[0])) { > FspData->PerfData[FspData->PerfIdx] = AsmReadTsc (); > ((UINT8 *)(&FspData->PerfData[FspData->PerfIdx]))[7] = Id; > + return FspData->PerfData[(FspData->PerfIdx)++]; > } > > - return FspData->PerfData[(FspData->PerfIdx)++]; > + return (UINT64)0x0000000000000000;
return 0; Works just as well. You also don't need a cast. https://godbolt.org/z/e5vvGcWWo -- Pedro -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#105074): https://edk2.groups.io/g/devel/message/105074 Mute This Topic: https://groups.io/mt/98993286/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
