[NTOS:MM] Fix PFN lock usage

ntoskrnl/mm/balance.c

@@ -77,6 +77,8 @@ NTSTATUS
 NTAPI
 MmReleasePageMemoryConsumer(ULONG Consumer, PFN_NUMBER Page)
 {
+    KIRQL OldIrql;
+
     if (Page == 0)
     {
         DPRINT1("Tried to release page zero.\n");
@@ -85,8 +87,12 @@ MmReleasePageMemoryConsumer(ULONG Consumer, PFN_NUMBER Page)
 
     (void)InterlockedDecrementUL(&MiMemoryConsumers[Consumer].PagesUsed);
 
+    OldIrql = MiAcquirePfnLock();
+
     MmDereferencePage(Page);
 
+    MiReleasePfnLock(OldIrql);
+
     return(STATUS_SUCCESS);
 }
 

ntoskrnl/mm/freelist.c

@@ -566,10 +566,9 @@ NTAPI
 MmDereferencePage(PFN_NUMBER Pfn)
 {
     PMMPFN Pfn1;
-    KIRQL OldIrql;
     DPRINT("MmDereferencePage(PhysicalAddress %x)\n", Pfn << PAGE_SHIFT);
 
-    OldIrql = MiAcquirePfnLock();
+    MI_ASSERT_PFN_LOCK_HELD();
 
     Pfn1 = MiGetPfnEntry(Pfn);
     ASSERT(Pfn1);
@@ -596,8 +595,6 @@ MmDereferencePage(PFN_NUMBER Pfn)
         DPRINT("Legacy free: %lx\n", Pfn);
         MiInsertPageInFreeList(Pfn);
     }
-
-    MiReleasePfnLock(OldIrql);
 }
 
 PFN_NUMBER