Re: [edk2-devel] [PATCH] SourceLevelDebugPkg DebugCommLibUsb3: Address NULL ptr dereference case

["Wu, Hao A" <hao.a.wu@intel.com>]

> -----Original Message-----
> From: devel@edk2.groups.io [mailto:devel@edk2.groups.io] On Behalf Of
> Zeng, Star
> Sent: Friday, August 09, 2019 9:54 AM
> To: devel@edk2.groups.io
> Cc: Zeng, Star; Wu, Hao A
> Subject: [edk2-devel] [PATCH] SourceLevelDebugPkg DebugCommLibUsb3:
> Address NULL ptr dereference case
> 
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2051
> 
> Original code GetConfigTable for AddrPtr first, if failed,
> InstalConfigTable with allocated AddrPtr. So the AddrPtr
> should not be NULL and the NULL pointer dereference case
> should be false positive. This patch is just to address
> the case raised from static analysis.
> 
> Cc: Hao A Wu <hao.a.wu@intel.com>
> Signed-off-by: Star Zeng <star.zeng@intel.com>
> ---
>  .../DebugCommunicationLibUsb3/DebugCommunicationLibUsb3Dxe.c    | 2
> +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git
> a/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCom
> municationLibUsb3Dxe.c
> b/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCom
> municationLibUsb3Dxe.c
> index eee30c852ffd..d4245465ce74 100644
> ---
> a/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCom
> municationLibUsb3Dxe.c
> +++
> b/SourceLevelDebugPkg/Library/DebugCommunicationLibUsb3/DebugCom
> municationLibUsb3Dxe.c
> @@ -447,7 +447,7 @@ DebugCommunicationUsb3DxeConstructor (
>    EFI_EVENT                     Event;
> 
>    Status = EfiGetSystemConfigurationTable (&gUsb3DbgGuid, (VOID **)
> &AddrPtr);
> -  if (EFI_ERROR (Status)) {
> +  if (EFI_ERROR (Status) || (AddrPtr == NULL)) {


Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
And pushed via commit 4053587347.

Best Regards,
Hao Wu


>      //
>      // Instead of using local variables, install system configuration table for
>      // the local instance and the buffer to save instance address pointer.
> --
> 2.21.0.windows.1
> 
> 
>