Re: [edk2-devel] [PATCH] MdeModulePkg/SdBlockIoPei: Add check for DeviceIndex

["Zhang, Shenglei" <shenglei.zhang@intel.com>]

> -----Original Message-----
> From: Wu, Hao A
> Sent: Wednesday, October 30, 2019 3:15 PM
> To: devel@edk2.groups.io; Zhang, Shenglei <shenglei.zhang@intel.com>
> Cc: Ni, Ray <ray.ni@intel.com>
> Subject: RE: [edk2-devel] [PATCH] MdeModulePkg/SdBlockIoPei: Add check
> for DeviceIndex
> 
> > -----Original Message-----
> > From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
> > Zhang, Shenglei
> > Sent: Thursday, October 17, 2019 2:21 PM
> > To: devel@edk2.groups.io
> > Cc: Wu, Hao A; Ni, Ray
> > Subject: [edk2-devel] [PATCH] MdeModulePkg/SdBlockIoPei: Add check
> for
> > DeviceIndex
> >
> > DeviceIndex is used as index in Slot[]. The max size of Slot[]
> > is SD_PEIM_MAX_SLOTS. So DeviceIndex should be checked before used.
> >
> > Cc: Hao A Wu <hao.a.wu@intel.com>
> > Cc: Ray Ni <ray.ni@intel.com>
> > Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
> > ---
> >  MdeModulePkg/Bus/Sd/SdBlockIoPei/SdBlockIoPei.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/MdeModulePkg/Bus/Sd/SdBlockIoPei/SdBlockIoPei.c
> > b/MdeModulePkg/Bus/Sd/SdBlockIoPei/SdBlockIoPei.c
> > index 8fa58d65b22c..25530dcb34ce 100644
> > --- a/MdeModulePkg/Bus/Sd/SdBlockIoPei/SdBlockIoPei.c
> > +++ b/MdeModulePkg/Bus/Sd/SdBlockIoPei/SdBlockIoPei.c
> > @@ -174,7 +174,7 @@ SdBlockIoPeimGetMediaInfo (
> >
> >    Private   = GET_SD_PEIM_HC_PRIVATE_DATA_FROM_THIS (This);
> >
> > -  if ((DeviceIndex == 0) || (DeviceIndex > Private->TotalBlkIoDevices)) {
> > +  if ((DeviceIndex == 0) || (DeviceIndex > Private->TotalBlkIoDevices) ||
> > (DeviceIndex > (SD_PEIM_MAX_SLOTS - 1))) {
> 
> 
> Hello,
> 
> I do not think the change is proper, since 'DeviceIndex' is used to access the
> array Private->Slot[SD_PEIM_MAX_SLOTS] like:
> 
>   Private->Slot[DeviceIndex - 1]
> 
> I think the change should be:
> 
>   ... || (DeviceIndex > (SD_PEIM_MAX_SLOTS)
> 
> instead of:
> 
>   ... || (DeviceIndex > (SD_PEIM_MAX_SLOTS - 1)
> 
> 
> Could you help to double confirm on this? Thanks in advance.
> 

Hao,

You are right. The index used below the if statement is " DeviceIndex -1" not " DeviceIndex ".

Thanks,
Shenglei

> Best Regards,
> Hao Wu
> 
> 
> >      return EFI_INVALID_PARAMETER;
> >    }
> >
> > @@ -252,7 +252,7 @@ SdBlockIoPeimReadBlocks (
> >      return EFI_SUCCESS;
> >    }
> >
> > -  if ((DeviceIndex == 0) || (DeviceIndex > Private->TotalBlkIoDevices)) {
> > +  if ((DeviceIndex == 0) || (DeviceIndex > Private->TotalBlkIoDevices) ||
> > (DeviceIndex > (SD_PEIM_MAX_SLOTS - 1))) {
> >      return EFI_INVALID_PARAMETER;
> >    }
> >
> > --
> > 2.18.0.windows.1
> >
> >
> >