MdeModulePkg/SecurityPkg Variable: If a preexisting variable is rewritten with differ...

[mirror_edk2.git] / MdeModulePkg / Universal / Variable / RuntimeDxe / Variable.c

diff --git a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
index 09b8b4bd21d2f76e93515d12baa656237857342d..d31fe0c871d634e24fbf29f0bc94590165fc60f0 100644 (file)
--- a/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
+++ b/MdeModulePkg/Universal/Variable/RuntimeDxe/Variable.c
@@ -2275,9 +2275,9 @@ VariableServiceSetVariable (
   }\r
 \r
   //\r
-  // Not support authenticated variable write yet.\r
+  // Not support authenticated or append variable write yet.\r
   //\r
-  if ((Attributes & EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS) != 0) {\r
+  if ((Attributes & (EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS | EFI_VARIABLE_APPEND_WRITE)) != 0) {\r
     return EFI_INVALID_PARAMETER;\r
   }\r
 \r
@@ -2361,6 +2361,16 @@ VariableServiceSetVariable (
       Status = EFI_WRITE_PROTECTED;\r
       goto Done;\r
     }\r
+    if (Attributes != 0 && Attributes != Variable.CurrPtr->Attributes) {\r
+      //\r
+      // If a preexisting variable is rewritten with different attributes, SetVariable() shall not\r
+      // modify the variable and shall return EFI_INVALID_PARAMETER. Two exceptions to this rule:\r
+      // 1. No access attributes specified\r
+      // 2. The only attribute differing is EFI_VARIABLE_APPEND_WRITE\r
+      //\r
+      Status = EFI_INVALID_PARAMETER;\r
+      goto Done;\r
+    }\r
   }\r
 \r
   //\r