On 06/16/20 11:04, Zhiguang Liu wrote: > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2317 > To avoid leaking information from SMM, uninstall > EFI_SMM_CONFIGURATION_PROTOCOL at end of Dxe. > > Cc: Eric Dong <eric.d...@intel.com> > Cc: Ray Ni <ray...@intel.com> > Cc: Laszlo Ersek <ler...@redhat.com> > Cc: Rahul Kumar <rahul1.ku...@intel.com> > Signed-off-by: Zhiguang Liu <zhiguang....@intel.com> > --- > UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c | 37 > +++++++++++++++++++++++++++++++++++++ > UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf | 1 + > 2 files changed, 38 insertions(+) > > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c > b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c > index db68e1316e..a1b209e125 100644 > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.c > @@ -520,6 +520,33 @@ SmmReadyToLockEventNotify ( > return EFI_SUCCESS; > } > > +/** > + SMM End of Dxe event notification handler. > + > + To avoid leaking information from SMM, uninstall > EFI_SMM_CONFIGURATION_PROTOCOL > + at end of Dxe. > + > + @param[in] Protocol Points to the protocol's unique identifier. > + @param[in] Interface Points to the interface instance. > + @param[in] Handle The handle on which the interface was installed. > + > + @retval EFI_SUCCESS Notification handler runs successfully. > + **/ > +EFI_STATUS > +EFIAPI > +SmmEndOfDxeNotify ( > + IN CONST EFI_GUID *Protocol, > + IN VOID *Interface, > + IN EFI_HANDLE Handle > + ) > +{ > + gBS->UninstallProtocolInterface ( > + gSmmCpuPrivate->SmmCpuHandle, > + &gEfiSmmConfigurationProtocolGuid, &gSmmCpuPrivate->SmmConfiguration > + ); > + return EFI_SUCCESS; > +}
(1) I suggest setting "gSmmCpuPrivate->SmmCpuHandle" to NULL here. (2) I also suggest de-registering the gEfiSmmEndOfDxeProtocolGuid notification. Thanks Laszlo > + > /** > The module Entry Point of the CPU SMM driver. > > @@ -1038,6 +1065,16 @@ PiCpuSmmEntry ( > ); > ASSERT_EFI_ERROR (Status); > > + // > + // register SMM End of Dxe notification > + // > + Status = gSmst->SmmRegisterProtocolNotify ( > + &gEfiSmmEndOfDxeProtocolGuid, > + SmmEndOfDxeNotify, > + &Registration > + ); > + ASSERT_EFI_ERROR (Status); > + > // > // Initialize SMM Profile feature > // > diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf > b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf > index 76b1462996..bb994814d6 100644 > --- a/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf > +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/PiSmmCpuDxeSmm.inf > @@ -105,6 +105,7 @@ > gEfiSmmConfigurationProtocolGuid ## PRODUCES > gEfiSmmCpuProtocolGuid ## PRODUCES > gEfiSmmReadyToLockProtocolGuid ## NOTIFY > + gEfiSmmEndOfDxeProtocolGuid ## NOTIFY > gEfiSmmCpuServiceProtocolGuid ## PRODUCES > gEdkiiSmmMemoryAttributeProtocolGuid ## PRODUCES > gEfiMmMpProtocolGuid ## PRODUCES > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#61339): https://edk2.groups.io/g/devel/message/61339 Mute This Topic: https://groups.io/mt/74912556/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
