Replace regfltr sample calls to ExAllocatePoolWithTag with ExAllocate…

…PoolZero. (#501)
microsoft · Oct 15, 2021 · f5fb15f · f5fb15f
1 parent 7895dd2
commit f5fb15f
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Showing 5 changed files with 26 additions and 21 deletions.
diff --git a/general/registry/regfltr/sys/capture.c b/general/registry/regfltr/sys/capture.c
@@ -443,9 +443,9 @@ Return Value:
         return Status;
     }
 
-    TempBuffer = (PCALLBACK_CONTEXT) ExAllocatePoolWithTag(
-                        PagedPool, 
-                        Length, 
+    TempBuffer = (PCALLBACK_CONTEXT) ExAllocatePoolZero(
+                        PagedPool,
+                        Length,
                         PoolTag);
 
     //
@@ -550,16 +550,14 @@ Return Value:
 
     DestString->Length = SourceString->Length;
     DestString->MaximumLength = SourceString->Length + sizeof(WCHAR);
-    
-    DestString->Buffer = (PWSTR) ExAllocatePoolWithTag(
-                            PagedPool, 
-                            DestString->MaximumLength, 
+
+    DestString->Buffer = (PWSTR) ExAllocatePoolZero(
+                            PagedPool,
+                            DestString->MaximumLength,
                             PoolTag);
 
     if (DestString->Buffer != NULL) {
 
-        RtlZeroMemory(DestString->Buffer, DestString->MaximumLength);
-
         //
         // It's a good practice to keep the contents of a try-except block to 
         // the bare minimum. By keeping the pool allocation call outside of the 

diff --git a/general/registry/regfltr/sys/driver.c b/general/registry/regfltr/sys/driver.c
@@ -162,6 +162,12 @@ Return value:
                DPFLTR_ERROR_LEVEL,
                "RegFltr: Use ed nt!Kd_IHVDRIVER_Mask 8 to enable more detailed printouts\n");
 
+    //
+    //  Default to NonPagedPoolNx for non paged pool allocations where supported.
+    //
+
+    ExInitializeDriverRuntime(DrvRtPoolNxOptIn);
+
     //
     // Create our device object.
     //

diff --git a/general/registry/regfltr/sys/regfltr.vcxproj b/general/registry/regfltr/sys/regfltr.vcxproj
@@ -177,24 +177,28 @@
     <ClCompile>
       <ExceptionHandling>
       </ExceptionHandling>
+      <PreprocessorDefinitions>POOL_NX_OPTIN;POOL_ZERO_DOWN_LEVEL_SUPPORT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
     <ClCompile>
       <ExceptionHandling>
       </ExceptionHandling>
+      <PreprocessorDefinitions>POOL_NX_OPTIN;POOL_ZERO_DOWN_LEVEL_SUPPORT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
     <ClCompile>
       <ExceptionHandling>
       </ExceptionHandling>
+      <PreprocessorDefinitions>POOL_NX_OPTIN;POOL_ZERO_DOWN_LEVEL_SUPPORT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <ExceptionHandling>
       </ExceptionHandling>
+      <PreprocessorDefinitions>POOL_NX_OPTIN;POOL_ZERO_DOWN_LEVEL_SUPPORT;%(PreprocessorDefinitions)</PreprocessorDefinitions>
     </ClCompile>
   </ItemDefinitionGroup>
   <ItemGroup>

diff --git a/general/registry/regfltr/sys/txr.c b/general/registry/regfltr/sys/txr.c
@@ -61,21 +61,20 @@ Return Value:
     //
     // Create the registry callback context and the transaction callback context.
     //
-    
+
     CallbackCtx = CreateCallbackContext(CALLBACK_MODE_TRANSACTION_ENLIST,
                                          CALLBACK_ALTITUDE);
     if (CallbackCtx == NULL) {
         goto Exit;
     }
 
-    RMCallbackCtx = (PRMCALLBACK_CONTEXT) ExAllocatePoolWithTag (
-                        PagedPool, 
-                        sizeof(RMCALLBACK_CONTEXT), 
+    RMCallbackCtx = (PRMCALLBACK_CONTEXT) ExAllocatePoolZero (
+                        PagedPool,
+                        sizeof(RMCALLBACK_CONTEXT),
                         REGFLTR_CONTEXT_POOL_TAG);
     if (RMCallbackCtx == NULL) {
         goto Exit;
     }
-    RtlZeroMemory(RMCallbackCtx, sizeof(RMCALLBACK_CONTEXT));
     CallbackCtx->RMCallbackCtx = RMCallbackCtx;
 
     //

diff --git a/general/registry/regfltr/sys/util.c b/general/registry/regfltr/sys/util.c
@@ -91,18 +91,16 @@ Return Value:
     PCALLBACK_CONTEXT CallbackCtx = NULL;
     NTSTATUS Status;
     BOOLEAN Success = FALSE;
-    
-    CallbackCtx = (PCALLBACK_CONTEXT) ExAllocatePoolWithTag (
-                        PagedPool, 
-                        sizeof(CALLBACK_CONTEXT), 
+
+    CallbackCtx = (PCALLBACK_CONTEXT) ExAllocatePoolZero (
+                        PagedPool,
+                        sizeof(CALLBACK_CONTEXT),
                         REGFLTR_CONTEXT_POOL_TAG);
 
-    if  (CallbackCtx == NULL) {
+    if (CallbackCtx == NULL) {
         ErrorPrint("CreateCallbackContext failed due to insufficient resources.");
         goto Exit;
     }
-
-    RtlZeroMemory(CallbackCtx, sizeof(CALLBACK_CONTEXT));
 
     CallbackCtx->CallbackMode = CallbackMode;
     CallbackCtx->ProcessId = PsGetCurrentProcessId();