Re: [edk2-devel] [PATCH v1][edk2-stable202002] MdeModulePkg/SdMmcPciHcDxe: Fix double PciIo Unmap in TRB creation (CVE-2019-14587)

["Wang, Jian J" <jian.j.wang@intel.com>]

Reviewed-by: Jian J Wang <jian.j.wang@intel.com>

Regards,
Jian

> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Wu, Hao A
> Sent: Monday, February 17, 2020 11:52 AM
> To: devel@edk2.groups.io
> Cc: Wu, Hao A <hao.a.wu@intel.com>; Wang, Jian J <jian.j.wang@intel.com>;
> Ni, Ray <ray.ni@intel.com>
> Subject: [edk2-devel] [PATCH v1][edk2-stable202002]
> MdeModulePkg/SdMmcPciHcDxe: Fix double PciIo Unmap in TRB creation (CVE-
> 2019-14587)
> 
> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1989
> 
> The commit will avoid unmapping the same resource in error handling logic
> for function BuildAdmaDescTable() and SdMmcCreateTrb().
> 
> For the error handling in BuildAdmaDescTable():
> The error is directly related with the corresponding Map() operation
> (mapped address beyond 4G, which is not supported in ADMA), so the Unmap()
> operation is done in the error handling logic, and then setting
> 'Trb->AdmaMap' to NULL to avoid double Unmap.
> 
> For the error handling in SdMmcCreateTrb():
> The error is not directly related with the corresponding Map() operation,
> so the commit will update the code to left SdMmcFreeTrb() for the Unmap
> operation to avoid double Unmap.
> 
> Cc: Jian J Wang <jian.j.wang@intel.com>
> Cc: Ray Ni <ray.ni@intel.com>
> Signed-off-by: Hao A Wu <hao.a.wu@intel.com>
> ---
>  MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
> b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
> index da5559ae76..43626fff48 100644
> --- a/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
> +++ b/MdeModulePkg/Bus/Pci/SdMmcPciHcDxe/SdMmcPciHci.c
> @@ -1544,6 +1544,8 @@ BuildAdmaDescTable (
>        PciIo,
>        Trb->AdmaMap
>      );
> +    Trb->AdmaMap = NULL;
> +
>      PciIo->FreeBuffer (
>        PciIo,
>        EFI_SIZE_TO_PAGES (TableSize),
> @@ -1753,7 +1755,6 @@ SdMmcCreateTrb (
>        }
>        Status = BuildAdmaDescTable (Trb, Private->ControllerVersion[Slot]);
>        if (EFI_ERROR (Status)) {
> -        PciIo->Unmap (PciIo, Trb->DataMap);
>          goto Error;
>        }
>      } else if (Private->Capability[Slot].Sdma != 0) {
> --
> 2.12.0.windows.1
> 
> 
>