diff --git a/reactos/ntoskrnl/mm/npool.c b/reactos/ntoskrnl/mm/npool.c
index 4cff298c7fe..08629b3e0aa 100644
--- a/reactos/ntoskrnl/mm/npool.c
+++ b/reactos/ntoskrnl/mm/npool.c
@@ -1556,14 +1556,12 @@ VOID STDCALL ExFreeNonPagedPool (PVOID block)
    {
       if (blk->hdr.Magic == BLOCK_HDR_FREE_MAGIC)
       {
-         DbgPrint("ExFreePool of already freed address %x\n", block);
+         KeBugCheckEx(BAD_POOL_CALLER, 0x07, 0, (ULONG_PTR)blk, (ULONG_PTR)block);
       }
       else
       {
-         DbgPrint("ExFreePool of non-allocated address %x (magic %x)\n",
-                  block, blk->hdr.Magic);
+         KeBugCheckEx(BAD_POOL_CALLER, 0x46, (ULONG_PTR)block, 0, 0);
       }
-      ASSERT(FALSE);
       return;
    }
 
@@ -1684,6 +1682,12 @@ ExAllocateNonPagedPoolWithTag(POOL_TYPE Type, ULONG Size, ULONG Tag, PVOID Calle
    return(block);
 }
 
+ULONG NTAPI
+EiGetNonPagedPoolTag(PVOID Block)
+{
+     return ((HDR_USED*)((ULONG_PTR)Block - HDR_USED_SIZE))->Tag;
+}
+
 VOID
 INIT_FUNCTION
 NTAPI
diff --git a/reactos/ntoskrnl/mm/pool.c b/reactos/ntoskrnl/mm/pool.c
index c326a492a2a..67d617279f4 100644
--- a/reactos/ntoskrnl/mm/pool.c
+++ b/reactos/ntoskrnl/mm/pool.c
@@ -21,6 +21,12 @@ extern MM_STATS MmStats;
 
 /* FUNCTIONS ***************************************************************/
 
+ULONG NTAPI
+EiGetPagedPoolTag(IN PVOID Block);
+
+ULONG NTAPI
+EiGetNonPagedPoolTag(IN PVOID Block);
+
 static PVOID STDCALL
 EiAllocatePool(POOL_TYPE PoolType,
                ULONG NumberOfBytes,
@@ -28,22 +34,39 @@ EiAllocatePool(POOL_TYPE PoolType,
                PVOID Caller)
 {
    PVOID Block;
+   PCHAR TagChars = (PCHAR)&Tag;
 
-   /* FIXME: Handle SESSION_POOL_MASK, VERIFIER_POOL_MASK, QUOTA_POOL_MASK */
-   if (PoolType & PAGED_POOL_MASK)
-   {
-      Block = ExAllocatePagedPoolWithTag(PoolType,NumberOfBytes,Tag);
-   }
-   else
-   {
-      Block = ExAllocateNonPagedPoolWithTag(PoolType,NumberOfBytes,Tag,Caller);
-   }
+   if (NumberOfBytes == 0)
+       KeBugCheckEx(BAD_POOL_CALLER, 0x00, 0, PoolType, Tag);
+   if (Tag == 0)
+       KeBugCheckEx(BAD_POOL_CALLER, 0x9b, PoolType, NumberOfBytes, (ULONG_PTR)Caller);
+   if (Tag == TAG('B','I','G',0))
+       KeBugCheckEx(BAD_POOL_CALLER, 0x9c, PoolType, NumberOfBytes, (ULONG_PTR)Caller);
 
-   if ((PoolType & MUST_SUCCEED_POOL_MASK) && Block==NULL)
-   {
-      KeBugCheck(MUST_SUCCEED_POOL_EMPTY);
-   }
-   return(Block);
+#define IS_LETTER_OR_DIGIT(c) (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z') || ((c) >= '0' && (c) <= '9'))
+   if (!IS_LETTER_OR_DIGIT(TagChars[0]) &&
+       !IS_LETTER_OR_DIGIT(TagChars[1]) &&
+       !IS_LETTER_OR_DIGIT(TagChars[2]) &&
+       !IS_LETTER_OR_DIGIT(TagChars[3]))
+       KeBugCheckEx(BAD_POOL_CALLER, 0x9d, Tag, PoolType, (ULONG_PTR)Caller);
+
+    /* FIXME: Handle SESSION_POOL_MASK, VERIFIER_POOL_MASK, QUOTA_POOL_MASK */
+    if (PoolType & PAGED_POOL_MASK)
+    {
+        if (KeGetCurrentIrql() > APC_LEVEL)
+            KeBugCheckEx(BAD_POOL_CALLER, 0x08, KeGetCurrentIrql(), PoolType, Tag);
+        Block = ExAllocatePagedPoolWithTag(PoolType, NumberOfBytes, Tag);
+    }
+    else
+    {
+        if (KeGetCurrentIrql() > DISPATCH_LEVEL)
+            KeBugCheckEx(BAD_POOL_CALLER, 0x08, KeGetCurrentIrql(), PoolType, Tag);
+        Block = ExAllocateNonPagedPoolWithTag(PoolType, NumberOfBytes, Tag, Caller);
+    }
+
+    if ((PoolType & MUST_SUCCEED_POOL_MASK) && !Block)
+        KeBugCheckEx(BAD_POOL_CALLER, 0x9a, PoolType, NumberOfBytes, Tag);
+    return Block;
 }
 
 /*
@@ -222,29 +245,40 @@ ExAllocatePoolWithQuotaTag (IN POOL_TYPE PoolType,
  * @implemented
  */
 #undef ExFreePool
-VOID STDCALL
+VOID NTAPI
 ExFreePool(IN PVOID Block)
 {
-   ASSERT_IRQL_LESS_OR_EQUAL(DISPATCH_LEVEL);
-
-   if (Block >= MmPagedPoolBase && (char*)Block < ((char*)MmPagedPoolBase + MmPagedPoolSize))
-   {
-      ExFreePagedPool(Block);
-   }
-   else
-   {
-      ExFreeNonPagedPool(Block);
-   }
+    if (Block >= MmPagedPoolBase && (char*)Block < ((char*)MmPagedPoolBase + MmPagedPoolSize))
+    {
+        if (KeGetCurrentIrql() > APC_LEVEL)
+            KeBugCheckEx(BAD_POOL_CALLER, 0x09, KeGetCurrentIrql(), PagedPool, (ULONG_PTR)Block);
+        ExFreePagedPool(Block);
+    }
+    else
+    {
+        if (KeGetCurrentIrql() > DISPATCH_LEVEL)
+            KeBugCheckEx(BAD_POOL_CALLER, 0x09, KeGetCurrentIrql(), NonPagedPool, (ULONG_PTR)Block);
+        ExFreeNonPagedPool(Block);
+    }
 }
 
 /*
  * @implemented
  */
-VOID STDCALL
+VOID NTAPI
 ExFreePoolWithTag(IN PVOID Block, IN ULONG Tag)
 {
-   /* FIXME: Validate the tag */
-   ExFreePool(Block);
+    ULONG BlockTag;
+
+    if (Block >= MmPagedPoolBase && (char*)Block < ((char*)MmPagedPoolBase + MmPagedPoolSize))
+        BlockTag = EiGetPagedPoolTag(Block);
+    else
+        BlockTag = EiGetNonPagedPoolTag(Block);
+
+    if (BlockTag != Tag)
+        KeBugCheckEx(BAD_POOL_CALLER, 0x0a, (ULONG_PTR)Block, BlockTag, Tag);
+
+    ExFreePool(Block);
 }
 
 /*
diff --git a/reactos/ntoskrnl/mm/ppool.c b/reactos/ntoskrnl/mm/ppool.c
index fbbf20a739f..2575c8c37a3 100644
--- a/reactos/ntoskrnl/mm/ppool.c
+++ b/reactos/ntoskrnl/mm/ppool.c
@@ -103,6 +103,12 @@ ExFreePagedPool(IN PVOID Block)
 	RPoolFree ( MmPagedPool, Block );
 }
 
+ULONG NTAPI
+EiGetPagedPoolTag(IN PVOID Block)
+{
+    return RBodyToHdr(Block)->Tag;
+}
+
 
 #ifdef PPOOL_UMODE_TEST