All Tianocore stewards,
I'd like to include the below patch (a revert patch) in this stable tag release.
It's to fix a potential security hole when platform mis-configures the
PcdCpuFeaturesUserConfiguration.
Thanks/Ray
> -----Original Message-----
> From: edk2-devel <edk2-devel-boun...@lists.01.org> On Behalf Of Ruiyu Ni
> Sent: Tuesday, November 13, 2018 3:35 PM
> To: edk2-devel@lists.01.org
> Cc: Kinney, Michael D <michael.d.kin...@intel.com>; Laszlo Ersek
> <ler...@redhat.com>; Dong, Eric <eric.d...@intel.com>
> Subject: [edk2] [PATCH] UefiCpuPkg/CommonFeature: Always set
> FEATURE_CONTROL.Lock
>
> The patch reverts commit 1ed6498c4a0210204bf4b95cc0c0cd6623ad6a0b
> * UefiCpuPkg/CommonFeature: Skip locking when the feature is disabled
>
> FEATURE_CONTROL.Lock bit is controlled by feature
> CPU_FEATURE_LOCK_FEATURE_CONTROL_REGISTER. The commit 1ed649
> fixes
> a bug that when the feature is disabled, the Lock bit is cleared.
> But it's a security hole if the bit is cleared when booting OS.
> We can argue that platform needs to make sure the value
> of PcdCpuFeaturesUserConfiguration should be set properly to make
> sure feature CPU_FEATURE_LOCK_FEATURE_CONTROL_REGISTER is enabled.
>
> But it's better to guarantee this in the generic core code.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ruiyu Ni <ruiyu...@intel.com>
> Cc: Eric Dong <eric.d...@intel.com>
> Cc: Laszlo Ersek <ler...@redhat.com>
> Cc: Andrew Fish <af...@apple.com>
> Cc: Leif Lindholm <leif.lindh...@linaro.org>
> Cc: Michael D Kinney <michael.d.kin...@intel.com>
> ---
> UefiCpuPkg/Library/CpuCommonFeaturesLib/FeatureControl.c | 11 +--------
> --
> 1 file changed, 1 insertion(+), 10 deletions(-)
>
> diff --git a/UefiCpuPkg/Library/CpuCommonFeaturesLib/FeatureControl.c
> b/UefiCpuPkg/Library/CpuCommonFeaturesLib/FeatureControl.c
> index 631c836857..8c1eb5eb4f 100644
> --- a/UefiCpuPkg/Library/CpuCommonFeaturesLib/FeatureControl.c
> +++ b/UefiCpuPkg/Library/CpuCommonFeaturesLib/FeatureControl.c
> @@ -1,7 +1,7 @@
> /** @file
> Features in MSR_IA32_FEATURE_CONTROL register.
>
> - Copyright (c) 2017 - 2018, Intel Corporation. All rights reserved.<BR>
> + Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
> This program and the accompanying materials
> are licensed and made available under the terms and conditions of the BSD
> License
> which accompanies this distribution. The full text of the license may be
> found at
> @@ -184,15 +184,6 @@ LockFeatureControlRegisterInitialize (
> {
> MSR_IA32_FEATURE_CONTROL_REGISTER *MsrRegister;
>
> - //
> - // When Lock Feature Control Register feature is disabled,
> - // just skip the MSR lock bit setting.
> - // The MSR lock bit is cleared by default and write-once in a boot.
> - //
> - if (!State) {
> - return RETURN_SUCCESS;
> - }
> -
> //
> // The scope of Lock bit in the MSR_IA32_FEATURE_CONTROL is core for
> // below processor type, only program MSR_IA32_FEATURE_CONTROL for
> thread 0 in each
> --
> 2.16.1.windows.1
>
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