2 files changed, 35 insertions, 0 deletions
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
index 8f10425eb..956c1f2ae 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
@@ -2756,6 +2756,11 @@ VariableCommonInitialize (
   ASSERT(VariableStoreHeader->Size == VariableStoreLength);
     
   //
+  // The max variable or hardware error variable size should be < variable store size.
+  //
+  ASSERT(MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxHardwareErrorVariableSize)) < VariableStoreLength);
+
+  //
   // Parse non-volatile variable data and get last variable offset.
   //
   NextVariable  = GetStartPointer ((VARIABLE_STORE_HEADER *)(UINTN)VariableStoreBase);
diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
index 2a59ac16f..2fca25981 100644
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/VariableSmmRuntimeDxe.c
@@ -198,6 +198,16 @@ RuntimeServiceGetVariable (
     return EFI_INVALID_PARAMETER;
   }
 
+  if (*DataSize >= mVariableBufferSize) {
+    //
+    // DataSize may be near MAX_ADDRESS incorrectly, this can cause the computed PayLoadSize to
+    // overflow to a small value and pass the check in InitCommunicateBuffer().
+    // To protect against this vulnerability, return EFI_INVALID_PARAMETER if DataSize is >= mVariableBufferSize.
+    // And there will be further check to ensure the total size is also not > mVariableBufferSize.
+    //
+    return EFI_INVALID_PARAMETER;
+  }
+
   AcquireLockOnlyAtBootTime(&mVariableServicesLock);
 
   //
@@ -275,6 +285,16 @@ RuntimeServiceGetNextVariableName (
     return EFI_INVALID_PARAMETER;
   }
 
+  if (*VariableNameSize >= mVariableBufferSize) {
+    //
+    // VariableNameSize may be near MAX_ADDRESS incorrectly, this can cause the computed PayLoadSize to
+    // overflow to a small value and pass the check in InitCommunicateBuffer().
+    // To protect against this vulnerability, return EFI_INVALID_PARAMETER if VariableNameSize is >= mVariableBufferSize.
+    // And there will be further check to ensure the total size is also not > mVariableBufferSize.
+    //
+    return EFI_INVALID_PARAMETER;
+  }
+
   AcquireLockOnlyAtBootTime(&mVariableServicesLock);
 
   //
@@ -355,6 +375,16 @@ RuntimeServiceSetVariable (
     return EFI_INVALID_PARAMETER;
   }
 
+  if (DataSize >= mVariableBufferSize) {
+    //
+    // DataSize may be near MAX_ADDRESS incorrectly, this can cause the computed PayLoadSize to
+    // overflow to a small value and pass the check in InitCommunicateBuffer().
+    // To protect against this vulnerability, return EFI_INVALID_PARAMETER if DataSize is >= mVariableBufferSize.
+    // And there will be further check to ensure the total size is also not > mVariableBufferSize.
+    //
+    return EFI_INVALID_PARAMETER;
+  }
+
   AcquireLockOnlyAtBootTime(&mVariableServicesLock);
  
   //