[PATCH 4/6] MdeModulePkg/Variable/RuntimeDxe: permit MorLock deletion for passthru req

[Laszlo Ersek <lersek@redhat.com>]

The SetMorLockVariable() function sets "mMorLockPassThru" to TRUE
temporarily, so that it can set the MOR Control Lock variable to
well-formed values without permission checks.

In the next patch, we'll need the same override for deleting the MOR
Control Lock variable; hence obey "mMorLockPassThru" in the deletion
branch of SetVariableCheckHandlerMorLock() as well.

Cc: Eric Dong <eric.dong@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Ladi Prosek <lprosek@redhat.com>
Cc: Star Zeng <star.zeng@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
index 24b7ffb84ce7..1f495f847212 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/TcgMorLockSmm.c
@@ -169,7 +169,10 @@ SetVariableCheckHandlerMorLock (
   // Basic Check
   //
   if (Attributes == 0 || DataSize == 0 || Data == NULL) {
-    return EFI_WRITE_PROTECTED;
+    //
+    // Permit deletion for passthru request, deny it otherwise.
+    //
+    return mMorLockPassThru ? EFI_SUCCESS : EFI_WRITE_PROTECTED;
   }
 
   if ((Attributes != (EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS)) ||
-- 
2.14.1.3.gb7cf6e02401b